21st in Miami - What’s the ideal day for a couple?

Hi everyone, I’m sure these get posted pretty often but I’ll be turning 21 on Saturday and plan to spend the day, sunrise to sundown, in the city.

For context: Gf (will be 20) and I are staying in Fort Lauderdale for spring break but making the trip in to celebrate for the day.

If you had to plan an ideal, 1 day trip to Miami what are good ideas? Brunch spots, activities, coffee shops, shopping, great places to grab first (legal) drinks (maybe places that wouldn’t be so strict w her still being 20), etc. Literally anything!

Any help would be appreciated!