I was a complete noob when it came to gunsmithing, until this year. I just built, alongside my a family member for some processes, three AR-15's from parts only, for different family members and myself.
You will need more than just basic tools, for the lower, and the upper. A poster on the first page probably forgot some of the tools needed. While building the stripper lower receiver is the most complicated part of the process,and requires the fewest specialty tools, the rest of the rifle will require specialty tools.
You will need a punch set, or just a few punches with with the curved "ball" end, roll spring punches. You will need some agility, a second set of hands, or a vice and a mag block that fits into the magazine well and vice, to sturdy the lower so you can hammer in the roll springs. I made my own mag block, with a beat up unuseable polymer mag I had laying around. Filled it with sand and epoxy on ends and drilled a dowel rod through it so the lower receiver sits on it where it should without having to rely on an installed mag catch. Or, buy one at a gun shop for $15. Most people do not have roll spring punches around, so you will need to buy one size for the lower, and at least one size extra for the upper.
The buttstock is considered part of the lower. Unless you are using an A1 or A2 style buttstock, you will need a buttstock wrench to tighten up the castle nut that keeps the stock attached to the lower receiver extension (that is essentially screwed into the back of the lower receiver).
So now - you can just buy an assembled upper, or build one yourself.
The upper will require parts you can't just can rig up yourself (or at least shouldn't unless you are already a machinist). You will need a small punch for the gas tube, and I think the same 3/16 punch for the A1/A2 sight assembly unless you are using a low profile gas block a picatinny rail front sight.
You will also need a torque wrench (for 20- 90 foot-lbs, actual, after converting it for the barrel wrench style you will also need need). You don't need a fancy barrel wrench, just get the GI version, use the torque wrench in parallel so you don't have to calculate actual torque.
You will also need an upper receiver action block so you can install the barrel. The upper receiver fits into the action block which forms a case around the upper receiver which you put into a vice. Or something similar to a Geissele Automatics action rod. If installing a delta ring (if not doing a free float handguard) you can get away with typical tools, just have to be careful)
You will need some special tools you might be able to rent or borrow, or some you have to buy.
roll spring punches (and hammer, no soft ends)
upper action block
lower action block
torque wrench
vice
youtube any videos you need, and go to brownells to watch their videos. You will not need every tool they have, buy you will need some of the specialty tools to completely assemble a rifle.