heyy i need some help with probability.. its not really one question, im just asking for some general help wiht the following:

what is conditional probability? any formulas? when do i need to use conditional probability?

what about formulas for independent and dependent events? when do i use these formulas? here is where i am confused because i dont know when to use conditional probablity, or when events are dependent or independent.

and when do i use combination and permutation formulas? what are they looking for in these types of problems?

and then there's that whole thing about trees, when do i use a tree to find probability?

i hope someone can help me! thanks a lot!