The gun you choose should have a big enough caliber to do the job (9mm is near bottom end, although .380 is still acceptable), should have recoil that you can handle, should have a trigger pull that doesn't disturb your accuracy (3 to 5 pounds is considered good), and should fit your hand. I'm partial to 1911 and derivatives. I don't like Glocks, but that's a personal thing. They don't fit my hand. My daughter loves her Glock 17. I've never found a revolver that fits my hand, but my wife's house gun is a Ruger .357 Magnum revolver. She has big hands.
Go to a gun store that will let you handle a variety of guns to see what fits your hand, and has acceptable trigger pull. If possible, try a variety of guns at a range. Some gun training courses supply guns (possibly at a fee). Take one of those and try several guns.
As others have pointed out, you will have to buy from a FFL, even if you buy mail-order from out of state. Talk to one near you and see if they'll let you handle several guns.
Good advice and I am in the process of setting up to follow it.
Finding a gun that feels right is important. I’ve had hand operations in both hands, so that will be an issue.
I’m looking into an FFL that will accept the purchase.
Thanks and Cheers! ‘Pod.