My Roughed In Bathroom Floor Is Not Level So When The Toilet Was Installed It Was Not Level, The Shower Seems To Be Leaking From Underneathe What Can I Do

The toilet can have shims under it to level it out, as for the shower leaking, nothing much than tearing it out, anything you do from up top will just be a temporary fix
You can try regrouting and grout sealer to start,