Every songwriting style is different, there's no right or wrong way. Some people write the music first, others the lyrics first, and some write them both together. Elton John is famous for beginning his career writing music to someone else's lyrics (that only appeared in the mail with out explanation) so there's no one to say it can't happen.
I think its great that you are trying and trying to improve. I'm not on this site all the time and I'm a bit busy, but the next time I promise I'll sit down and help you with your english and we can get you started with something you can be proud of. Ok?
