If you have problem with menus there are a few things I can say.
For different menu screens you can make different screens in the same level and just move the camera, that way you don’t have to make things overlap each other and you don’t need to code as much.
For pop ups you can also make background objects that look like the previous screen, this way when you teleport the camera it looks like a seamless transition. It makes sure that the player can’t click anything in the background and you don’t need make more code to make the buttons appear.
Also, just from a design view point, try to keep everything simple, sometimes people try to fit a lot of info into one screen or clutter everything with buttons and text.