Assuming you are still using the trial version, it does have limitations, you can only export 3 mins of video, in a limited range of formats adn some features do not work.
For the full version, I would advise purchasing the Plus or Premium version, the main difference is the extra effects - see comparison here.
For uploading to YouTube, I export the video to my PC and check it before using YouTubes web uploader - saves those embarrassing moments when you spot an error or some thing in the background of the video that should not be there.
Get the program as a download from the MAGIX site and go for the Premium version. It is nearly always on offer so don't pay full price. On offer it is exceptionally good value but do check your PC specs meet the minimum requirements if not, preferably going beyond them some bit for best results. If you are not sure about that, come back with your PC specs in full and we will advise.
As per what Ray indicated, Movie Edit Pro Premium is currently on sale for less than Plus.
YouTube seems to change its upload algorithm often and thus programs like Movie Edit Pro cannot upload automatically until the next version. And then YT changes again. As John EB indicated, it's best to export to MP4, check that it is ok (play it back on a viewer) and then upload using the YT site. You may also want to export a frame from the video to a jpg file, like a frame with a title, to be used as the thumbnail for YT.