Nice choice! Lot of value for the $$ IMHO. I'm fairly new the the AR world as well, this site has a lot of info. I have a Stag 3TL (lefty) and have been very happy with it. I think the only difference is that yours have the fixed front sight, where I have a low profile gas block. Anyway, as mentioned above, a red dot optic is great. I put an EoTech 512 on mine and could not be happier. Not great for long range work, but for under 200 yards it's very effective, probably will add the flip out of the way magnifier when funds free up. Target aquisition with the EoTech is immediate, almost like cheating. The EoTech and a sling are all I'm doing ti mine, kinda keeping it simple.
Mine came really dry, so a quick field strip and good lube before your first outing may be a good idea, Breakfree CLP mentioned above works well.
Ammo wise, the only thing mine has not liked was PMC Bronze, had some fail to fire's (about 10 out of 100 rounds) with what looked like good primer strikes. So not sure if it was ammo (hard primers maybe) or what. It eats Remington UMC (.223) well, American Eagle (red box .223) well and XM193 (5.56) well. Zero issues with any of the ammo other than PMC. Have not tried steel cased stuff, probably will stay away from it. The trajectory difference between the .223 and 5.56 ammo seems significant, so you may want to choose one or the other as your go to ammo.
Enjoy!