Have you already installed the new cam? Or just planning ahead? (and that's good, if you are)
What you're talking about for using HPT on your truck is feasible.
If you don't have a recent Windows laptop, it'll run fine on Win10. If you're figuring to get a new laptop, and have Win11 pre-installed as part of that, that's fine too. But you can get a new machine with Win10 cheaper, if you look.
I found my HPT on my local Craigslist. It was the older version, but it did have the MVPI module, and 8 credits purchased. I've used two for my Sierra. If I want to write / alter my Envoy's tune (that another person did), that'll take another two credits (most vehicles are 2 credits, and they run about $50 for each credit). HPT changed their licensing, so now you buy credits (and they're universal, for any make / model, not manufacturer-specific, like they used to be).
The MVPI module allows remote logging without having to connect the laptop, and it provides analog pinouts (for connecting a wideband O2, for example). But you can purchase without the module and work around it, or upgrade later at a reduced cost.
The software is in two parts... the editor, and the logger. You connect via the OBD-II port. A cable is provided, and it uses USB at the PC end.
You use the editor to download your OEM tune, then modify it away from the truck and write it back when you're ready. You can also open another tune (from another vehicle, etc.) for an A <-> B comparison (the 'B' tune is presented 'read-only').
Once you write the tune back to your PCM, it overwrites what's on there. So you want to keep the original copy for safekeeping (you can write the original one (or any previous one) back; that gets rid of any changes you made in the interim). The PCM will still adapt fuel trims, etc. -- but it's doing that to whatever tune is on the PCM.
After the tune is written, then you use the logger portion to record the engine outputs, then lather, rinse, repeat (until you've got it where you want it).
Costs:
You can buy the (newest) software from HPT direct. But you can probably find it a little cheaper elsewhere. And if you want to buy used, you can save even more. If the old owner had registered it, you can change the licensing (but you have to call HPT support). And you'll need at least 2 vehicle credits to be able to save a tune to your hard drive (even the OEM one).
As far as tunes... you can get samples from HPT's online repository (I have several); you look for something similar and start from there. Those are free.
Besides that, there's a forum on HPT's site, and some people there will build a tune (for a fee); you establish contact with them, and e-mail your OEM file; they modify it after discussing what you have / what you want, send it back via e-mail and you upload it / test / provide feedback. The top guys will generally have you 80% or better to bright with the first file they send. You're at their mercy for 'how much will this cost' (e.g.; I haven't used their services, so I don't know what they charge).
One of our members (Limequat) does tunes for GM trucks, and he uses HPT. I had him do my Envoy and another truck (not the one I'm doing now). If you have a Envoy / Trailblazer, you won't find anyone cheaper, as he discounts those, due to his own interest in the platform.
IIRC, he charged about $150 to do my other truck. That was over 3yrs ago, so you'll want to check with him. His site is at limeswap.com
Generally, you take your ECM out of the truck, send it to him via USPS; he configs and uploads the tune to your ECM, and sends it back via USPS. You plug it back in, start the truck, and you're done (unless you want / need more done later). Follow-up work is $25 (again, discounted aggressively).
He'll also send you the copy of the OEM tune for safekeeping, etc., if you request it, and he doesn't lock the tune he sends you. If you're wanting the truck tuned without having to get a copy of the software, he's probably your safest bet.
Other 'mail order' tunes (Black Bear, et al): generally in the $500 and up range. Works basically the same as Limequat above, but costs more. These are supposed to be optimized when you get them, but they're often called 'cookie cutter' tunes, as well. Sometimes power can be left 'on the table' with the generic tunes, but they should be very drivable (and should pass emissions, if you have to have your vehicle tested periodically).
If you would rather deal with someone local, they'll probably be in the $500 and up neighborhood, too (you know from your phone calls what your local people are charging). Again, you don't need your own copy of HPT, but you're at their mercy for any changes. The upside to local places is that they'll often have a dyno (or access to one), and dyno runs will / can be included in the price (they upload a base tune, do a run, tweak, do another run, etc.) So what you get back should be optimized for your exact truck (and they should take a good 2-3 hours to do the work, at a minimum).
So... with all that said... do you want to 'roll your own', and try and tune your own truck?
The milder the cam, the easier it'll be to get a base tune figured out (because there's less to change). But the value in having someone experienced do it is to get additional power (40-80hp) via changing other parameters / tables. Can you learn to do it? Sure. How patient are you?
You say you're not really PC savvy... so if I were to judge based on that, I'd say you might want to lean on someone to do the heavy lifting, and save the cost of purchasing the software, etc.
My background / professional career had me working with computers, etc., so the software itself wasn't bad -- for me. A lot of it is in tables, row / column based, so if you're familiar with spreadsheets, you'll feel at home. The difficulty will lie in what to update those values to, and in what tables, besides. There's no 'instructions', for the most part. But the basic order you want to do things is: 1) airflow, 2) fueling (using a wideband O2 sensor, preferably), and only after those things are worked out, 3) timing / spark.
Now, there *are* videos on You Tube, etc., that go over how to get started, some forum posts, etc. If you review those things, and really understand them, then you could conceivably do it. It won't be fast, and as someone mentioned... it's an ongoing process (you may be tinkering with things for a year or more, depending). I have mine running well, for now... but now I need to fine-tune things, which I'm waiting to do until I swap out my intake and fuel injectors (the OEM injectors are too small, plus I want to be able to run E85). That's the part that takes the longest time -- optimizing.
My own cam wasn't really radical, so I was able to start the truck and it ran, with the OEM tune. It ran really rough, but it ran. Some cams are so hot that the truck won't initially start / run. For those, you often have to temporarily raise the idle speed and add a couple degrees of timing until you get the airflow established, then back the idle speed back down and go from there.
IIRC, there were about 10 tables, and 100 or more parameters that I reviewed / changed to get the truck running as well as it runs now. I also had to do things in stages -- I couldn't change everything at once. Rather, I had to change some things, run the truck, record values, and use those to make the next changes, etc. Sometimes I had to wait for the engine to cool down 6-8 hours before I could run the next procedure. You get the idea. But if I were to guess, it probably took me about 5 sessions over 2-3 days before I had a good basic tune in the truck. And I probably spent a week reviewing 'how' to do it, before I changed a thing.