New AR guy here as well. I stumbled on an used one (Bushmaster carbine) from a buddy. Afterwards I hit the google button and YouTube. YIKES!
I wouldn't attempt to recommend a specific brand/model. But, I can say this: don't go wild and crazy trying to keep up with the advanced AR upgrade guys. After shooting mine the first time I discovered I needed two changes, a rubber butt stock pad for the hard plastic Tapco adjusting stock and a rubber Magpul pistol grip. Find a middle of the road AR manufacturer and do your personal upgrades...slowly. Good luck.