What airline are you flying? If you are flying Southwest, then you need to check in online 24 hours prior to your flight time in order to get your boarding pass. Other airlines where you chose your seat when you book you do not need to do this. Some airlines, like Airtran to save money you can wait to chose your seats 24 hours prior to your flight, so if you are flying Airtran and did not pick your seats, check in 24 hours prior.
The day of your flight, ( I always get there 2 hours prior so that if there are lines for check in or security I am not stressed out) when you get to the airport you can generally do one of two things, you can check in curbsite, which is what I do because usually the line is shorter. When you do this you present your boarding pass and your ID or your ticket and your ID and then the person at curbside will print your boarding pass if you just have your ticket tag your bags for MCO, you should tip this person $1 a bag. You hold on to your carry on luggage, they will tell you which gate to go to for your flight, and then you are off to stand in line for security.
If you opt to check in inside (some airports do not have curbside check in and some airlines may charge a fee) you go inside and stand in line, when it comes your turn to get to the counter, most airlines have a kiosk where you key in your flight # or confirmation # and the number of bags your are checking and then your boarding pass will be printed there. The person behind the counter, checks your ID, takes your bags, generally they weigh them to be certain they are not over weight, your bags are tagged to go to MCO (you do not tip the people inside) and off you go to stand in line for security.
When you get to the line for security you will need your boarding pass and ID. Make sure you have checked the TSA website for what you are allowed or not allowed to carry on. You will need to take off your shoes, and if you are wearing a jacket or sweater you must take that off as well, you put those item in the bins and put your carry on and the bins on the conveyor belt and these items are scanned. You pass through the screener the person checks your boarding pass again (and maybe your ID too, I am not sure) once you are done there you are now able to go over to your gate.
Is that helpful?