So you'd be coming up I-4, you'd go past Universal Blvd to Kirkman Road and head north. The exit to Kirman road is in the left lane of I-4, you'll see the signs. After you exit, go a mile north, over a bridge, and turn left at Conroy Road.
There's also a Publix on Sand Lake Road just west of I-4 on the south side of the road. But I like the one at Conroy Road and Kirkman the most. You can visit www.publix.com and check locations in the Orlando area. There's also a Walgreens across the street from the parking garages. There's a SuperWalmart 5 miles north of the parks on Kirkman Road.
I have the address in there, it's 4606 S Kirkman Road Orlando FL 32811. So you could pull up a map program and ask for directions from MCO to the Publix and you'll have it.