Don’t let fear get in the way. An ar is the simplest gun on the planet. How complex can it really be? Jar heads use it’s cousin so you know that are simple lol.
From the time I lock an 80% lower in the vice till I’m shooting it is about 2 hours.
If I start with a completely milled lower it’s only about 45 min from pile of parts till bang including mounting the barrel to the upper without lapping the upper first.
You can get away without even having an armorer’s wrench depending on what barrel nut your hand guard uses.