Version control is something that will save your behind if you screw really up. Happens sooner or later. Unfortunately, most explanations for version control is for CLI lovers. There are 2 flavours: centralised (SVN) or decentralised (GIT).
There are - of course - tools for both. There are a couple of videos by Xojo showing how to get started with version control.
The purists will tell you that only the text format will make you happy. To save your behind even the binary format with external items is enough. Don’t ever do a monolithic project.