Our first trip to Daytona Raceway we took the track tour. The tour tram heads through the turn 4 tunnel and the infield area (including the new fan zone/garages). It's a slow pace and but only last 20-30 minutes.
After/before the tram tour, you can walk up to the grandstands and lookout at the track, there's also a "closeout" gift shop there where you might find some great deals compared to the main gift shop.
If you want to spend more time and $$$, the Daytona USA interactive area , including this years Daytona 500 winning car, would take another hour or more.
We always go to Daytona when in the Orlando area.
Have fun.