How i train my voice and singing very well?

if you think you voice is good
join a choir they will teach you how to sing and breath properly so your voice comes from with in
also it cost nothing

Find a song that has a lot of high and low notes and sing along to it. for instance, Foundations by Kate Nash because of the accents used. For starters, sing along every morning, from loud to soft. make sure you have the lyrics though.