I want to become a singer at the age of 13 but I don't have drums guitars and stuff o and I can't lower my voice like a singer

Most importantly can you actually sign or is this an unachievable dream?

Yea first of all see if you can actually sing. Record your own voice or ask your family and friends to give an honest opinion.
After that there are several ways: start singing in coffees, bars or somewhere public and hope for an opportunity to appear. You can also sign in a show like "America's got talent" and get as far as you can. If you really are a good singer someone will come and talk to you. But you need to do something to prove that you aren't just another face in the crowd.
If you can't sing very well but that is still your dream, then do something. Start training on your own or have singing classes.
Good luck!

Find a agent or agent or a trainer to help with your voice fist of all.then sing in contests and in church(if you go).then someone will hear you and get you a agent.

Agreed, where are you singing now ? You will need to find places to sing, also many places will not allow you to sing "covers" because of the money that has to be paid, so you need to start working on some of your own songs.

Coffee houses, nursing homes and other places are a good place to start