Minecraft PC IP: play.cubecraft.net
Hi! We wouldn’t give achievements/experience out for nothing, but it really could be any number of things. You could’ve played for a bit and forgot about it, a family member with access to the account could have played on it, etc. If you’re worried about someone having had unauthorized access to your account, you can always change your password and enable 2FA on your Microsoft account. Overall though I couldn’t tell you exactly what resulted in you getting the levels, but it likely is not any problem :)
