For self-defense? Barnes Triple Shok. For target practice? Whatever ammo you can get your hands on that is of decent quality and price. PMC X-Tac, XM855, XM193, Lake City M855 etc etc.
First off, congratulations on the carbine. It should serve you well.
For defensive ammo I would go with either Black Hills Mk. 262 mod 1 with the 77 grain OTM or Hornady 5.56 TAP 75 grain (the latter is REALLY hard to find!). Defencive ammo thread here.
And plink with whatever is cheapest.
If you need more info, the search button is your friend. Good luck!
I second that recommedation. I also use Hornaday .223 75gr TAP. While not loaded as fast as 5.56 specs, it will do the job if you can’t find 5.56 TAP or Mk262. BTW - This is LE TAP in the red box we are recommending, not the FPD TAP in the black boxes.
Triple Shock, mentioned above makes a nice hunting round, but it is a lot more expensive than TAP or Mk262 (approx $18 more than Mk262 for a 50rd box.)
For plinking, I usually use XM193 55gr FMJ. I have been finding Federal Lake City with a little searching for $290-310/1000rd.
You’ve forgotten two very informational forums. No need to bother asking the question there, I guarantee that you can find excellent answers within the stickies and recent threads.