That is a very broad question, because it depends on what you mean. You can use a handgun for target shooting, competitive matches, or self defense.
You posted the question under the State and Federal law category. If you are referring to laws, the law varies from state to state, so it depends on what you mean and in which state you are located.
the state of Missouri does not require handgun registration.
mostly, glocks
Glock 17
Follow the instructions in the owner's manual.
No. Only use what is stamped on the barrel.
It depends on where you are. In the U.S. 11 year old children cannot own a handgun, but it is legal under federal and most states' laws to possess the handgun for legal purposes such as hunting and target shooting.
Yes, rubbing alcohol can be used to clean a handgun. It is effective for removing dirt, residue, and oils from the gun's surfaces. Make sure to follow all safety guidelines and manufacturer recommendations when cleaning your handgun.
I believe it was a Walther P99
It depends on the specific agency.
Point it at what you want to hit and pull he trigger.
I'll give the answer a shot (no pun intended). It depends on the circumstances. The handgun permit and handgun permit laws allow you legally carry a handgun, but the handgun permit laws don't specify when you can use the gun. When you can use the gun is covered under the state's deadly force laws. So, if a snake is attacking you and you have no other choice but to shoot it, it's probably ok. If you're talking about randomly shooting snakes that you see on the side of the highway or somewhere, probably not.
No. Generally speaking, you can only use the correct caliber magazine for any given handgun, and .380 and 9mm are not interchangeable.