There is no "best caliber" because it depends on several things. If the child is new to shooting, a .22 is probably a good choice. They don't have much recoil, they are easy to shoot, and ammo is cheap. Many people start beginners on .22s.
Best to ask a gunsmith for help
It all depends on you, your pocketbook, your skills.
Can't be answered without knowing what caliber, intended use, make of firearm
Assuming you mean a bullet fired from a .22 caliber handgun, the answer is, yes, it can, but it depends on several variables.
Yes, colt makes a few different versions of the 22 caliber handgun such as the Woodsman, and Challenger.
It should be marked as to caliber on the barrel.
Its the size of the bullet that the gun is made for. its the caliber that a handgun uses
No.
.32 caliber. In a semi auto handgun, probably .32 ACP
Probably. It would likely refer to a handgun that fires a .45 caliber ACP, or .45 GAP or an older .45 caliber revolver round.
45 has the larger projectile. Size of the handgun will vary.
$489!!