how to compose a song?

[prussian blue]

lol any tutorial how to make a song? i'm quite interested in music and i'm tending to write my own music. i wrote alot of lyrics but i found its hard to compose a melody for it. i only wrote once and quite lucky it sounds good. but i just want to know how to compose a song with the proper sequence

and question here
1. what is an arrangement?
2. how to arrange music?


thx for the advance