How to outgrow a perm and maintain healthy hair?

I'm an 18 year old African American girl. I have perked my hair for about five years. My hair isn't very damaged because I don't have bald spots or any hair loss, but I know perming your hair is not healthy at all. Perms have made the tips of my black hair look reddish brown and dry. Also, perming has made my hair thin, rather than it's natural thickness. I can't even remember what my natural hair looks like, but my mom said that it was really thick and kinky. I want to know what the first steps are for getting rid of my perm and going natural. Also, I know that while I'm waiting for my natural hair to grow back I should use braids or twists, but is it also possible to use a flattening iron to keep it straight every now and then? Thanks!