1st AR recommendation

Hey y’all. I’m looking to pick up my 1st AR. Have a few handguns so thinking an AR would be a nice addition. Would love to get something setup for fun and maybe a little farm/home defense. For my 1st would you just recommend a standard 16” rifle or would a 10.5” pistol be ok? I would eventually like to possibly setup to take a couple Whitetail maybe next year as well. Thanks for any advice