How do I get rid of my short curly hair?

I`m a guy, 17, I have short curly hair, I hate it. I want medium to longish wavy or straight hair but my hair when it gets long t all turns into a fro. I just bought regis hair straightener, it says to blow dry hair, but guess what? never done that before. It basically stays the same except it smells better. What do I do to get longish to medium hair kinda like tom cruise in MI 2 since lots of people tell me I resemble him. Any help would do, any low cost no salon type deals will do my fine, but any suggestion would be good.