Can you be a little more specific as to where in Florida? There are plenty of golf courses, that will never be your problem. Generally speaking, we have an older population. No way to get around that. That being said, There are people your age too, you just may have to seek them out.
I am in the Ft. Myers area. This time of year you will probably pay $75 and up for a round with a cart. If you have the google, you can get prices a little more specific. Now when summer rolls around.....prices drop like a rock!!! You can get an afternoon special for $20-$25 after 3 pm. That being said, we usually get rain in the summer around that time. But as you will learn here quickly....if you don't like the weather, wait a while, it will change! A thunderstorm in the summer may be 20-45 minutes long. So Overall I think you will find a great choice of courses to chose from and will be able to find several that will fit your needs.