The best way and most flexible is to go to the top menu, File, Export Movie, Video as MPEG-4, click on Display all and the pop down the top box. I always use MP4 FullHD 1920x1080 29.97p. Magix has optimized the presets so I suggest that you not play with them under Advanced unless you really know what you are doing.
Yes. On the export screen, at the top right, save your setting with your name etc. Export. Next time, your preset will be on the shortened popdown list; no need to select Display all.