Exodus 9

I have a few questions about the plagues? Why were the magicians able to copy some of the plagues but not all of them and is there a significance as to why there are 10? And I know I have some crazy questions but why did God not just do the 10th plague first rather than go through everything? Don’t you wonder why Pharoh saw that the plagues weren’t affecting Moses and people why he didn’t realize God was with them?