The restaurant is a place to take your sims for a luxurious meal, located in the southwest of your sim town.
Unlocking
You will unlock the restaurant once you have started the Sous Judgemental Quest.
Repairing
The restaurant is repaired in segments.
You will have to buy each room and to be able to clear it up, which is needed for it to be useable. A blue exclamation point will appear above most items that need repairing, but not on all items, so if it looks broken, click on it and check if there is an option for it to be fixed.
Once you have completed the area, it will be fully useable. Here is a list of each area, what is inside it, how much it costs to repair, and how long it takes to be fully cleared.
Foyer:
Trash - 30 Minutes
Trash - 1 hour 30 Minutes
Paint Buckets - 2 Hours
Broken Tile - 3 Hours
2 Lamps - 4 Hours Each
Leaky Roof - 6 Hours
Broken Wall - 10 Hours
Total Time (If you only use 1 Sim) = 1 Day 7 Hours