I strongly suggest that you look for a shooting range or a Gun Store with a firing range that rents guns to try. Sometimes people just rent a gun that they can't afford to buy but they can afford to rent. Anyway, I suggest you try that and you will probably find one that feels good to you, the grip, weight, caliber, make, all of these are important.
Don't look for the cheapest, just look for the best you can afford and that feels good to you.
You also will be able to judge whether you will feel like carrying it, regularly. It's important that you judge for yourself, advise from friends, etc. is fine, but don't make your decision based on that. Also doing some reading about certain types of firearms will help, remember that this is an awesome responsibility. You have to be ready to destroy what you aim your firearm at.