Piece of cake..you'll be fine. A few things though...
1. Be sure to arrive at your airport about 2 hrs before departure time...yes, I know that seems like a long time. But, you'll have to go find a parking place, get to the terminal, check your bags, go through security, head to your gate. It's so much better to have plenty of time, especially if you aren't familier with the system.
Wear shoes that are easy on/off. Don't overpack your carryon. Be sure to put any toiletries in that clear quart size ziploc baggie. Any liquids, gels should be travel sized....3 oz, and should all fit comfortably in that baggie. When you get to the security area, take off your shoes, put them in a bin, take out your baggie, put that in the bin. Your carryon bag goes onto the conveyor belt, your coat/jacket goes in a bin. Any change or heavy watches, belt buckles should also come off and go in a bin, just to be on the safe side. All electronics should be inside the carryon bag. Then, you will be directed to a scanner, you walk through, with your boarding pass in hand (they will ask to see it), grab your things as they come out of the 'machine' put your shoes on, take your time..don't let yourself be rushed by those behind you. Put everything back together once you get it all off the conveyor belt (but, do step all the way down and off to the side to do this).
2. use the bathroom about 20 minutes before you board..boarding usually starts about 20-30 mins before take-off time.
3. Once on the plane, stow your carryon bag, under the seat if you can. This way you will have what you need right there and don't have to keep getting up. But, if you have a larger bag, put it in the overhead bin. What should you have in your carryon you ask? A book, magazines. A change of clothes, swim suit possibly, any medications you take, your official papers (passes, room reservation info)
4. Once that puppy is airborne...watch the flight attendents. If they look relaxed and are just going about their business, you're golden. Now, if they suddenly head to their little 'jump seats', strap in and sit there, white-knuckled, then you can start worrying. Hasn't happened to me yet though, so I wouldn't start worrying if I were you.
5. Take you time getting off the plane. There is no rush. You can't make those in front of you move any faster so just chill. Once off the plane, you'll head to the tram, which will let you off right by the security area. You'll be on level 3. Level 2 has baggage claim and level 1 has all the ground transportation. Follow the directions you get in your DME packet. You will go to the DME desk, checkin, then you will be directed to the proper bus line. you will go to your resort...no telling which of three stops you will be. My average time from deplaning to resort checkin has been 70 minutes....4 trips with DME.
Your bags will be taken from the plane to your resort where they will arrive 'magically' in your room up to three hours after your room becomes available to you.
Don't worry...that plane is built to be in the air..it wants to be in the air. The plane likes turbulance, the pilots like it a bit choppy...it's more interesting evidently...not for me, but for them. I just hate it when the pilot gets bored, don't you??!!
Anyway...have a great trip. All will be well. Do not have 3-4 drinks before getting on the plane, it doesn't help and just makes you obnoxious (that would be a 'general' you, not you personally!!!). Take some deep breaths, watch those around you. You'll be surprised how easy it is. Hope this info has helped a little bit...sorry it got so long.
but I can handle the flight of an airbus or a larger plane. I cannot ride the "puddle jumpers" b/c you feel every bump and turn. If you could ride on a school bus for any length of time, you will be fine during the flight. 
