Should you conserve space by having a single transforming button instead of two non functional ones?

I’m currently designing a webpage where users are asked to modify the positions of certain elements. Currently I have a single button to allow the users to enter “edit mode” which allows them to drag and move positions of sticky notes on the page. This is the only form of editing users can perform on the page. Currently, upon hitting the edit button, it transforms into the save button, which users are expected to hit after modifying the elements. I’m currently wondering if I should have a separate save button, even though it has no function except for when in edit mode. Having separate buttons would also conversely mean that the move button then becomes non-functional when in the edit mode. I’m curious if anyone has any thoughts about having one conservative/single button versus two buttons which are only functional if the other one has been pressed?