Here’s a map of the places I ate at (or wanted to eat at but didn’t make it to) when I was in Bangkok recently.
The food is excellent in Bangkok. Some things you MUST do:
Night market street food: either explore on your own or book a food tour with an experienced guide who will know the best vendor for all the most popular dishes, such as mango sticky rice
Mall food courts: the food at them is to die for and it’s such an easy way to try a ton of Thai dishes in a really clean and comfortable environment
High-end Thai food, at either Nahm or Bo.lan
Floating market: you’ll have to hunt for really good dishes but the whole experience, though super touristy, is really comical and fun
Just be prepared for (1) hella traffic, probably the worst I’ve ever experienced and (2) a culture where it feels like a lot of people are trying to scam money out of tourists, particularly taxi drivers.