For anyone intimidated by fine dining, I'd say approach it by recognizing that the people involved are really excited about providing a memorable experience for you, and that they've worked years at perfecting the whole performance of it, and making you feel comfortable and welcome (with adult boundaries) is their vocation. For a lot of professional waiters and cooks, it's like performing music, so be interested and curious and let yourself be delighted. It can also be a bit overwhelming, so even though you have probably eaten in restaurants before, treat fine dining like a new experience, as they've tried to make it one.

Professional staff can handle just about anything, and there's not much they haven't seen. The secret I think is to know before hand who is paying, have a sense of the budget from online menus before ordering so you don't have to focus on the prices, respect the personal boundaries of the servers, and if it's your first time, consider that you'd like to be welcome back.

I don't think any of them have a gong they smash whenever they see someone using their dinner fork for the salad, and some decorative table settings actually break with convention and can be a bit mystifying, so if you don't know what's what, ask. They can accomodate most things, but make dietary restrictions known during the reservation, as they'll usually prep for them. They're about providing a unique experience, so if your needs aren't medical, consider whether you're open to a new experience before spending a lot on one. Fine dining restaurants employ dozens of people with specialized skills, and provide livings that support families, so go, get treated like royalty for a bit, and use it as a waypoint for how well you can be treated and how good something as simple as food can be, then use the expereince to enrich your life.