Hello Logan b,
I can see why this is confusing, especially if you don’t know how you joined the group.
Please sign in with the affected account at Microsoft Family Safety and check the menu beside your name. Is Leave family group missing, or can you select it but then get an error? If there’s an error, what does it say?
That distinction matters: Microsoft’s guide to leaving a family group says a missing Leave family group option means the account is not an organizer, so an organizer would need to remove it. If the option is there but fails, the error message will help identify the next step.