Dating doesn't work at restaurants right now. It's a known issue. If you want your Sims to go out to a restaurant, do it as a group instead of a date. It only takes two Sims to make a group, so the only real differences are that you won't have to meet any goals and won't earn any rewards. Here's a link to the bug report thread. [DO] Can't request table in restaurant on a date/hangout | EA Forums - 4969313
Sims 4 dates work just fine at other locations I've tried. My Sims usually have at least one date a day, sometimes 3 or 4, and get gold on all of them. I just don't send them to restaurants. Dating was part of the game long before Dine Out, after all. Personally, I've always preferred home dates, where I don't have to worry about strangers butting in and making things awkward.