WE ALL GET STUCK SOMETIMES.
Your big hint is at the bottom of the page.
THE VAULT IS LOCKED.
Of course it is. This takes an 8-digit number.
OPENING THE VAULT
"Visitors" refers to the ABBA Album you found in the bench chest.
The Ballroom has a performance of the ABBA song "Dancing Queen"
The Electrical Room has a panel with A (36) and B (24) on it.
Enter the numbers for A-B-B-A to open the vault.
Remember all passwords are lowercase with no spaces.