Greetings and welcome to the forum.
For starters, become familiar with the 2 basic types of handguns, semi-auto and revolvers. Revolvers are the more traditional handgun seen in westerns and older movies, while semi-autos became more common during the last century.
Next, learn about calibers which start from the smallest (.17 caliber) and increase in size from there. Also, the smaller calibers are rim-fires which means the firing pin hits the cartridge rim containing the primer to fire the weapon, whereas the more prevalent type cartridge is a center-fire, which has a small primer inserted into the base of the cartridge which is hit by the firing pin to ignite the round.
The same is true with rifles. Some are single shot, some are manually operated with a bolt or pump, and others are semi-automatic.
A shotgun is the same way, single shot, bolt or pump, and semi-automatic.
No one expects you to be an expert, but you learn the basics differences, then everything else will make sense. Plus the folks here will be happy to help and answer any questions you might have.
Good luck.
