As EP says, there are no right or wrong ways to do stuff.
But a good point to start when creating is to copy other artists. So analyse what they do in terms of structure, maybe even analyse a ship-load of stuff so that you have some variation ideas as well.
I have a good primer on song structure that I wrote for senior high school/1st/2nd year college students, you may want to look at, check it out through my sig links.