You have a leg up as far as canoeing experience is concerned, but there's a definite risk of getting lost, especially the first time you're doing swamp canoeing. The terrain is different from other types of waters you've traveled, but according to my friends who have done swamp canoeing, there are things that you can do, both before you go, and during your trip, which will make it easier and more fun. This advice is based on their travels, not my own, but I believe it's pertinent and hope it's helpful.
Since you've picked your specific spot, check with local people who have navigated it before. Ask where the landmarks are, to help keep yourself oriented. Ask where the pitfalls are, such as areas of deeper drop off or a higher concentration of vegetation or other marine growth or rocks which might surprise you.
If it's a well-documented area for swamp travel, look for a guidebook which you can study beforehand. If it will fit in your gear, take it with you. Take a smaller map too.
If you know you'll have reliable GPS service, take the GPS with you. Program it beforehand, including stops at areas you may want to pull out along the way, either for safety or for sightseeing. Even if you have a GPS, take a compass.
Check weather forecasts before you go. If fog or stormy weather arises, it will make it harder for you to see where you are, especially since swamps are generally dark and murky already. Even if you're experienced in canoeing in difficult weather, this type of situation is different, so you might want to choose a time where the forecast is for clear skies. When the sun shines down into the swamp, you can see even subtle changes in the terrain under the water, which are helpful. Time of day is easier to measure by sun also.
If you're alone, let someone know where and when you'll be going. Check in with them when you get back, so they don't worry!
Take a camera! The swamp areas will give you glimpses or wildlife in, out, and under the water which you may never see in other areas where you canoe.