You're staying near Medieval Times, right? You have several options, but the Beeline Expressway isn't one of them - that'll take you to the I-4 and then in the wrong direction entirely (although you could get off at the 535 Apopka Vineland Road, but you'd be contending with far busier roads than is necessary and going out of your way).
Actually, I wouldn't take the 417 either, although that is an option (and it's the best route for anyone staying anywhere west of Old Town).
As you leave the airport, you need to follow the signs for the 417 Central Florida Greeneway. It's very well signposted. You'll travel along the South Access Road for 2-3 miles before hitting the Greeneway. Rather than take that, I would be temtpted to carry on for another couple of miles until you hit the Boggy Creek Road, making sure you take it west, and then pick up the Osceola Parkway (again travelling west). OP is a free-flowing toll road. Exit at the John Young Parkway and head south (JYP actually becomes Bermuda Avenue at that point, but the exit should still be marked JYP). Once you hit the 192, you'll need to travel west for 2-3 miles. Wal-Mart and Medieval Times are between markers 15 and 14.
If you do decide to take the Greeneway, be careful not to miss the exit. It's a right-hand ramp (remember you'll be driving on the right, so stay in the right lane). If you pass under a road bridge, you've missed the exit (the road above you will be the 417!). Again, exit at John Young Parkway and head south, which will take you onto Bermuda Avenue.
I hope I haven't confused you - from what you say you've obviously got a map, so, if you look at it, what I've said should make some sense.