Will Updated Theme Erase Previous Customization

Newbie here - If I update my theme (it’s been 3 years since I’ve worked on my website and I’m diving back in) - will my previous customizations be lost? Menus/fonts/colours/etc.
Thank you kindly for your help!

None of your customisations will be lost if you only played with settings, theme options. The only thing that will be lost is the changes you make directly in theme files (code changes) and if they are done in child theme, they won’t be lost.

Thank you so much for your reply @UnitedOver! I sincerely appreciate your help. I can’t remember if I made any code changes (probably not); however, I’ve made a backup just in case. Wish me luck!