I've installed a Ubuntu 22.04 VM on my windows computer (using virtual box), and whenever I use the sudo command on the unique, default session, I get the error "user not in sudoers file". How can I fix this ? I have tried to run the recovery mode in root mode, but I'm asked a password (which I never defined nor was given).
Isn't it weird that the default session doesn't have admin permissions ? I'm guessing this isn't usually the case, but it's been like this on every ubuntu vm I've created.

Any help will be greatly appreciated, thank you !