Well, Disneyland does have Mr. Lincoln...

If you're leaving from someplace near Virginia, Auto-Train is the way to go. You'll have your car available when you get there. Sanford isn't far from Orlando. Tickets can be unobtainium at popular times of year, though, and it's expensive.

Otherwise ... you're probably better off flying to Orlando and renting a car at the airport. Rentals at Amtrak stations are tough to arrange, anywhere. OTOH, Ubers or even hotel shuttles might be available at Kissimmee or Orlando that get you to your hotel, then you can arrange shuttles to the parks (Disney and Universal, especially) from there, if you don't want to drive.

Later this year (more likely next year), you might be able to take the train to Orlando Airport from Miami (Brightline).