Shark valley is about 90 minutes from Ft Myers, if you have a lead foot, but 2 hours with traffic..
Its on Highway 41 about maybe 60 miles east of Marco Island if you know where that is.
And if you mean the tower, that is a spiral walk up ramp to the observation tower at the southern point of the tour.
Basically the entrance to the park is on 41, and its about an 8 mile walk/bike ride to the tower and another 8 miles or so back on the return loop. You can take a trolley (not sure if thats every day) and I think you can rent a bike too.
Only go during the season, which is November thru April. Any other time and youre likely to be swarmed by mosquitoes.
Interweb it.
Nearby there are some private airboat tour operators. They tend to be the large barge cattleboat variety where they pack on 15 people, but you can get a smaller more private boat for more money.