General question

Hello, I'm Abir. I've some simple questions to ask because I'm little confused about those. My first question is: what is the meaning of or difference between "to do" and "to be done"? Second question: "will" is future form and "would" is past form, but I see many times "would" is used as future form as well, but 'when would I use' "would" mentioning the 'future'? Third question: "could" is also past form, but used as mentioning the future instead of "can" 'when should I use "could" instead of "can" to mentioning the future? And last question: what does mean of "would" and "would have" and their differences, please explain? Advanced thanks for answering my questions.