Your son needs to go to the Rok Brgr Miami location and send you a pic of his visit.
ROK:BRGR | burger bar & gastropub
I read the Ft Lauderdale Sun Sentinel and it usually has restaurant reviews up and down the coast, incl Miami resto's , best morning or all night breakfast spots/ dive bars, best wings, best Cuban/ Haitian / Carib / a zillion ethnic foods for days etc. On the cheap and expensive. Now that I look, even via their search I can't find nary a one other than Ft L centric.
I quit reading the Miami Herald some time ago. Forget why.
MiamiHerald.com - Miami & Ft. Lauderdale News, Weather, Miami Dolphins & More
I am pretty sure they publish an entertainment and weekender's guide. If he looks ahead to what's happening Next week or so, he may be able to plan around an event or something.
Jr lived in South Fl for several years ( which had several built in advantages) and other than going to Tampa last year and Disney another, we prefer going to S Fl on winter vacations. We were in Deerfield Beach 2 weeks this winter. Miami is a vacationer's day trip for us and we are touristers' Tourists. Could I ever say where we had lunch or ahem, the early bird special. Why no. Why not. Because if we cross paths in the same area, we would as likely go to a new or different place. There are so many cuisines and restaurants to try.
I know when Jr. lived there, it took him a long time to strike up friendships outside of work. Perhaps he is more shy socially. I hope your son has a travelling buddy to share experiences with and someone to go exploring with.