Yeah, as you leave Orlando, there will be some traffic on I-4 heading west around Disney until you get to US-27. Then things pick up and you can go 80 for about an hour. You'll feel like you're on a long trip, and think it's going to take forever. Then you'll see I-75, and head north. You'll get off at Fowler Ave and go West. Now you pass thru a bunch of stop lights. You go past a museum on your left, you'll see the college on your right (University of South Florida). Then you'll see signs for BGT, get in the left lane. It's like the 2nd left after you see the college. The street name is called N. McKinley Drive, but the signs will show you the way. You'll cross some rail road tracks, drive a few blocks, and then you'll see the coasters in the distance. The parking lot is on the left just past Adventure Island.
If you're hungry, there are a bunch of places you could eat on Fowler Ave before you get to BGT. That could save you some money. So yeah, it may be a good idea to give yourself 2 hours. If you were to leave the Orlando at 06:30am, you'd avoid rush hour, and get to BGT at 08:30am when the parking lot opens. Then you'd be first to the gate, and get some walk on rides on Sheikra.