As much as i would like to say "Don't trust new players, Just because they say they were "new" doesn't mean they ARE" Not saying to insult you or anything just a fair warning in the future to be a bit careful on letting someone you don't know into your base.
This is why I only friend with trusting players, and trust from me is not easy it would take others a long week before they gain my trust
But even if i trust them...i still don't
Next time Don't friend strangers and let them into your base, As friending with others gives them claim permissions to damage and raid your base.
Only tell them the code for a "rented" room and not to your whole base.
It would be nice if the Devs of 7 days to die, create a permission option so that your "friends" Don't have permission to damage anything within your claim.