My my wife’s birthday coming up. She always wanted to go out and cook her own meal with me, with a chef. Where to go?

What's wrong with her cooking in her own kitchen?

I like the cooking school answer, but if you are looking to make it a single grand gesture, find someone available as a private chef (advertise in gigs on Craig's list?). This person could give you a shopping list based on his or your wife's menu, and arrive at your kitchen early afternoon. S/he would talk through the menu and explain the fine points of preparation, coach your wife on each step of each dish, and hopefully be willing to serve the two of you the dinner of  your wife's dreams.

I did a similar thing for my wife who wanted to know more about home decorating, and it worked out well (which is to say she liked the present).

Contact some of your local restaurants and ask them. But it may well Cost you  Any good chef would be willing to show off his talents

Do you know how to use google? Search for cooking class near me (with location turned on or use your zip code) - lots of places have 1-3 hour classes.

It is impossible to answer this question without knowing where you are, unless money is no object in which case I'd say go to France - but wait - there's a pandemic still going on.

I used to help with a local cooking school and one of the things we would do is go to peoples homes to do "cooking parties". We also hosted special events at our commercial kitchen/classroom.

I suggest you search in your area, or whatever radius you are willing to travel to, for similar situations where you can go on site and cook with a chef.

Alternatively, you could give her a set of cooking lessons at a cooking school.  These are typically led by a chef or chef teacher.  At our school we had the founder, main assistant and other kitchen assistants, then we always had a guest chef and a theme.  The guest chef would introduce the theme and recipes, talk for 1/2 hour or so about our theme, the food, how to, etc, then we'd break up into small groups and do the prep work then gather again as a group while the chef would lead us through the cooking of the various dishes.

Many hands make light work and it was AMAZING the feasts we would prepare with 12-25 sets of hands in 3 hours.