Welcome to the forum...
Just about anything can be carried if you have the right belt and holster. You should carry whatever you are most comfortable with.
Start with a good belt. Leather belt such as Beltman or Bullhide belts. (Not a Wally World cheapo.)or a tactical belt such as Wilderness. Crossbreed Supertuck is listed as the top carry holster in the forum. (But there are others that are very good.) The holster is going to come down to the weapon you choose.
I recommend going to at least a couple of reputable gun shops and discussing carry pistols with them. Handle as many guns as you can. Glock will come up a lot. I prefer M&P. (Both are fine.) Then find a place you can RENT AND SHOOT them. See what works for you! If at any point you feel like the guy behind the counter is leading you down a rosy path, walk away. The most expensive pistol in the case may not be the best for you.
The 9mm normally has less recoil and ammo is relatively cheap.
The .40 is more snappy, but many law enforcement agencies carry this round.
The .45 has been around forever, but the lighter the weapon, the higher the recoil.
Once you have you pistol. PRACTICE, PRACTICE, PRACTICE.... go home. Then practice some more.
Not trying to be condescending, I just don't know your level.