BetterPHP

Do you think I should go through the whole GD libary, learn everything and make functions ect? Because it seems kind of interesting, but is it worth it?

Its certainly a useful tool to know how to use. But there is not much point in memorizing all of the functions if that's what you mean

Nah just the useful ones

Well you can always use the manual pages so there is no need to actually learn the functions, you just need to know that they exist.

Just play around with it, that's the best way to learn things like this.