I really like the GitHub desktop app for branching and making commits especially for contributing to other people's open source projects. Having it be visually represented so well really helps me be confident I am not accidentally committing a file I shouldn't or overwriting some code unexpectedly.
It's lacking in capabilities for more complex git needs but as @alistaire mentioned, it's easy to switch back and forth to command line depending on what you need to get done!
If you want an interactive quick intro to git/github I really like: https://try.github.io/