Help In Excel 365

I am having a problem with the ruler not being able to move it from the right side anymore. I was able to at one time, but it's not letting me anymore. I set it up for a landscape orientation. It will let me move it down the bottom of the page and on the left side but not the ritht side anymore. How do I fix this or what am I doing wrong and how do I fix this? it's like it's locked or something.

How do I keep the page from splitting it two. It splits and I don't know how to get it to show only the one page as I can see both the page I'm working on which is the left side and the right side which looks like it's a continum but I'm not working on that side. How do I fix this? The right side is grayed out.

I would like to know how to determine the cell size. When I stretch a cell it will show what the lenghth is until I let go of it. My question is, where would I go to see the exact cell size I created showing me the measurments of that cell?