I'd to know if there is (idk) bus or train next to the miami aeroport?I'm asking cause i'm going to miami just?

there may be lockers but if u r headed to n.y. just check the bags and let them go straight through. u really don't need a carry on except maybe a book. ask a taxi how much to the beach and back do a map quest and see how far the airport is from the ocean u may not be close enough for that. but u can see the ocean while in new york. it is the same. and unfortunately the east coast waters are dirtier than the west coast. don't know why that is but been to both. not sure there is enough of a layover by time u hit the bathroom and find your way to the exit and all to do anything like that. a two hour layover would be more realistic. good luck