I've been in that same situation plenty of times, and eventually I figured out that nice photos online mean nothing if the place turns out to be disappointing. What actually works is looking at reviews, but not all the same way. If you see a restaurant with only super high ratings, they're almost always fake, so be skeptical. Look instead for ones with an honest average like 4 out of 5, where you find both positive comments and constructive criticism. Read especially the recent comments, because a restaurant can change a lot over time - maybe they switched chefs or the quality dropped.
Another signal I always use is checking whether people actually go there, not just for an ad photo. If the restaurant has up-to-date social media pages with real customers eating, if you see stories of people going back, that's a good sign. The menu is worth checking out beforehand too: a serious restaurant has prices that match what they offer, and the menu doesn't change in some weird way every week. If they do everything badly, better run away.
The last trick is calling them directly on the phone, like an hour before rush time. If they answer right away and are willing to give you info, they're people who care about service. If nobody picks up or they seem annoyed, the service will probably be terrible anyway. And if you really need to make a good impression, go somewhere already tested by people you know, don't just trust algorithms and influencers.