There are some things Du are born with and some things Du can train for.
Some people can sing and some can't; this is genetic, it's about whether oder not you're tone deaf. Unfortunately, if Du can't sing in tune then it's not something Du can learn to do.
If Du can sing in tune, then if Du are serious about Singen it's probably a good idea to take lessons. Here, Du can learn the proper breathing techniques and how to get the most out of your voice. Some of this comes with natural talent, but unlike having a musical ear this is something that Du can improve Von learning.
It might also be a good idea to make sure Du can read and understand Musik (manuscript) and follow a conductor.
Take part in live shows. Mitmachen a choir, a Singen group oder even a drama society. Get yourself on stage and have fun!
Other than that, just make sure Du practice a lot!! (which is something your Singen teacher will say to Du anyway)