Saving versions

[songsj]

I tried a search on this topic and could not find much. When I'm mixing in Reaper at times I would like to save a version of a mix and then try some other settings on another version. In Sony Vegas I believe all I had to do was do a save as and rename the project Like Blah version 1, I then could make changes and save it as Blah version 2. If I wanted to go back to version I just found the .veg file named Blah version 1, clicked on it and it brought me back to the original version. Does Reaper work this way as well? I also would like to know how to save audio renders. I render a file and burn it to cd fine. I find the render file in my Reaper project folder and I can tell it is the render by it's size but it is a .bin file that I cannot seem to open or re-import back into Reaper. What am I doing wrong? Thanks