Well.. I think first, you need to really enjoy singing.
Enjoy the music, enjoy the feelings, enjoy sharing music with
your friends and don't think of singing as a performance, as
something you are 'showing' to people, but just as a part of
yourself. Have a GOOD TIME!
Don't be a 'wanna be' - just BE someone who loves to sing, and
enjoys the expression of music. Everything else will come along~
whether it is joining a music school or a competition.
Then it wouldn't matter if you are good or bad (and since people
have praised you, at the very least, you can carry a tune!) and you
lose the consciousness and awkwardness that accompanies a
'performance'.