I would like to edit a PDF file with advanced functions or even with all functions but I can't find how

I'm using Acrobat Pro DC since a while and I know how to edit a file but there are many tools that aren't available in my editing options. Like I can't use my mouse to, let's say, draw around a particular spot on a page. That's only one of the many examples of what I can't do. I can add text, add a header but I can't use objects. Also, I'd like to quickly modify a format of some pages. I have a document that was scanned from a book. Some pages in my document are 1 page of the book which is good. Other pages in my document are 2 pages side by side of the book and the page in my document which includes 2 pages of my book is the same size as the page in my document that corresponds to 1 page of my book. I'd like to quickly convert the image including 2 pages to 2 distinct pages of correct size in my document. I have no tools for that. I had a normal Adobe Acrobat writer version prior to this Acrobat Pro DC version and it was way easier to use it and find what I needed. Now, with this DC version, there are so many add-ons that I can't find myself in there. I'm very disappointed by this DC version. It might be because I don't know how to maximize the use of it but then, if I don't know how to maximize it, it might be because it's too complicated...