The basic idea at low levels is just to play until you realize you need to do something you can't, then set a macro up for it as you go

The only real necessary ones to start out are some sort of targeting system (/assist, /focus, etc), and a /follow macro, and then at least 1 spell set up to go off when you push a button. An accept macro is nice for accepting quests. Beyond that, thats probably all you need to get to 60 unless you plan on instancing You can set up additional abilities on macros as you need them and tweak existing buttons as you realize they might not do exactly what you want them to. Its quite a large learning experience and as you go along you'll learn all sorts of stuff!