We definitely recommend the use/creation of a child theme when making modifications to the default theme, so we agree this is a good idea if that's what you're planning to do :)
You can find some useful documentation
here relating to customizing our themes, and in terms of "issues", really we simply recommend that you always back up before proceeding with theme version or even WordPress updates. If you already have experience with creating child themes then you'll already know that you'll reduce the risk of losing all of your changes in the process of an update, but that you'll still need to check for compatibility any time you do update. Thanks.