As stated above, you will not likely have 5500 lbs towing capacity. That number is before vehicle options, passengers (except 150 lb driver), pets and gear in the vehicle. You will be even more limited by payload. As mentioned above, best thing to do is load the truck up with passengers, pets and any gear that will be in it when towing. Then head to a scale and weigh it with a full tank of fuel (weigh each axle separately so you can see how much room you have on your rear axle as well). Take the total scaled weight of your truck and subtract it from your trucks gcwr to get your adjusted towing capacity. Take the total scaled weight of your truck and subtract it from your trucks gvwr to get your available payload. Take your scaled rear axle weight and subtract it from your trucks gross rawr to see how much room us,available on your axle. Your loaded tt weights should be less than these numbers. The tongue weight must be subtracted from your payload (and be less than room available on rawr). The overall trailer weight must be less than adjusted towing capacity. Your tongue weight and trailer weights must also be within your hitch specs.
Now when looking at the trailer, know that you will never tow a dry or unloAded tt. Most tend to add 1000-1500 lbs of cargo weight to a tt (think dishes, toiletries, chairs, wood, etc as it all adds up very quickly). Being as you do not yet know exactly how much weight you will add to your tt, it is safest to do all calculations using tt gvwr. The loaded tongue weight should be 13-15% of the loAded tt weight. Again in your case figure 13-15% of tt gvwr for a safety margin.
Without knowing your payload, I can't help you with specific numbers. I can tell you that you will likely need a trailer with a gvwr under 3500 lbs depending on where your actual scaled weights and payload numbers fall. I'm guessing this as hitch weight limits tend to be around 10% of towing capacity, so 10% would be 550 lbs. A 3500 lb tt could potentially have a tongue weight of 525 lbs. You are likely within range for something along the lines of a CasitA or scamp or a pop up. Good luck with your search.