Whatever you have. If the qualification was anything like mine, all you had to do is hit paper. I had people in my class that couldnt hit target (hit paper, but not the rings) at 7 yrds. They passed.
You can rent pistols of various calibers at many gun ranges. Since you are in Muskogee I don't know what would be closest for you. I do know that Medlock's in Collinsville has a number of pistols to rent and they cover many types and calibers. Try before you buy.
Taking additional training before you buy a pistol is also a good idea. Both USSA and TDSA provide basic handgun marksmanship training and can rent you a pistol for the class.
Keep in mind if you are going to carry you'll need a pistol that's not going to be left behind because it's too big to carry and conceal.
Train and practice until you can hit what you aim at reliably. If you want to buy a pistol to practice with buy a used one that you can get your money back out of when you decide on what you ultimately want. Of course, if you really enjoy shooting, what you ultimately want will change about once a month as new shiny/black/Flat Dark Earth/Olive Drab objects cross your field of view.
I wound up with a 9mm and and use 124 grain Gold Dot +P Short Barrel for carry purposes.
Dudn't matter. I like 9x19mm, but I've got .45s, too. No longer a fan of .40, but it's fine too. 9mm has higher capacity, lower recoil, and the FBI type tests show *almost* nearly the same expansion and penetration as the bigger ones.
Having fired the "qualification test" in a couple of CCW states... the guy who said if you can "miss safely" and get a licences was ab-so- loot-ly right. Oklahoma's range section is pretty minimal.
My MIL is CCW'ed in South Carolina. Tested with a .22 (Walther P22). By her own admission-- the insructor loaded her mags and cocked the gun for her the whole 50 round test. She had the gun locked up at our house for months... and asked for a little help when she retrieved it.
I made her load mags... then unload them. We went through the manual of arms (snap caps... her booger hook wont take the order to index on the guns frame) and "hey... don't point that gun at me again", did not seem to impress her either.
We never got outside to my rural, informal shooting range.... the little safety lever, and mag release had her baffled.. letting her shoot that thing anywhere near me was 'out of the question'.
If a state requires demonstration to get the permit it should be meaningful. I am glad that a high percentage (overall) get a permit and do no actually go heeled.
My Mom has a Alabama CCW... carrys a nice SW J frame... she will be very suprised by the noise it makes--- I don't think shes ever fired it at all. I offer... she excuses herself... so it goes.