Actually a single word”足” means foot. Like 足球 means football. So when you want express the meaning of enough , we usually connect 足 with other words. Like 足够 ,meaning enough. Or you can say 足量 meaning the number or the height is enough because 量means volume .
够 also can means (adj.)enough but we always connect this word with 了. 够了
I think it's difficult to remember the differences directly. You can practice with your tutor, which will make you master these words as soon as possible.
You are welcome to talk to me, and to ask me the other question you have if you would like to help me with engle else. :P