I have been towing trailers a long time. Here is my opinion, take it for what its worth.
The trailer will have the UVW (Unloaded Vehicle Weight) listed.
Figure on about 800 pounds above the dry weight to give you a ball park on the total weight you will be towing. Remember - passengers count against the vehicles towing capacity (at least some manufacturers list passengers as counting).
Check the total tow weight for the vehicle first, then shop for trailers. If the poster above is right and you are at 3,000 pounds you are really looking at a smaller pop-up rather than a travel trailer. The salespeople will tell you "it will be fine". It won't.
I try to keep the loaded weight to no higher than 80% of towing capacity just to be safe. This way you will have power for hills, etc., and it will be safer.
In all honesty, I wouldn't tow anything more than a pop-up with a RAV. It is not just the towing capacity, but the wheel base as well. It is really not meant to tow anything big, like a travel trailer. Safety first.