Well, it’s a peaking program, so it’s not really for building muscle. It’s for maximizing the one rep max in each of the movements.
If you look at the tonnage in each week, you’re still in what is more or less the introductory phase. Intensity is low, around 60%, which will bump up to 65% for week 4 and go up from there while rep count will decrease. It’s a fairly straightforward linear periodization program.
You’ll get stronger on it, because as a beginner you’ll get stronger doing just about anything. I encourage you to finish it, even if it’s suboptimal, because you’ll learn something from it and that’s the only way to get better as a lifter - keep learning.
When you’re done, I’d recommend getting on something like GreySkull LP. You’ll progress faster. After that, nSuns is usually a good program to run for increasing volume after the (lower volume) GSLP.
Also, generally speaking, 8 working sets for a given movement is actually a lot.
If you haven’t already, I’d recommend reading about progressive overload: https://rippedbody.com/principle-progressive-overload/
For other beginner programs, check out: https://liftvault.com/programs/powerlifting/beginner-powerlifting-programs/