Get a book on Spring Boot and jump back inro Java web development.
With git, you don’t need to master it, just find some subversion to git howto and start using it. It’s half a page of text. Once you learn the basics you can learn more as you go. There are many otherwise competent programmers who don’t know git too well, I know because I support them from time to time.
But you can uninstall them and install a lower version