I lived in Miami for years and did not need Spanish, though I would think it would be especially helpful for a nurse to have Spanish. You can go a bit west of Coral Gables on Bird Road - when my husband was at UM we lived near the intersection of Bird and Ludlum - and have a reasonable commute (which in Miami is still a pain, the traffic is abominable) while paying lower housing costs for a rented condo with community pools, etc. I also didn't drive when I first moved to Miami and biked or took the bus/metro; even once I drove we were able to be a one-car family. I'd still say you need a car for clinicals and to get out to places like Key Biscayne and the national parks- must recharge whenever possible! And when I say the traffic is abominable, I mean really an abomination, an outrage, a simulacrum of hell.
So be careful where you live. Avoid Kendall- parts of Kendall were quite lovely when I lived there but ten miles could take an hour to drive, and that's *no* exaggeration. Good luck, and do take advantage of what little downtime you have- South Florida can be a lot of fun.