Garage Band 10.1.0

I'm having several different problems with Garage Band, and was wondering if there is a way to get a fresh download of the app?

My op is OS X 10.10.5. I do not care to explain all the different problems, but I will try to be brief; 1) Problem with joining regions.

2) A new Garage Band folder was made, somehow, but not by me. The app started placing all my latest song.band files in this new folder.

The main folder is in Docs/Garage Band. The new folder is listed under music. 3) I was completing my latest song, about eight tracks, and the app

deleted one of my split folders at the end of the track, and in a separate track, the audio fades off on about the last third of the audio track.

If there is a download type file available, would that be from the app Store?