GVWR is Gross Vehicle Weight Rating
GAWR is Gross Axle Weight Rating
So you know the ratings for each axle and the whole vehicle which is clearly not the sum of the two axles. Now you need to find out how much your vehicle actually weighs in order to determine how much capacity is left for people, cargo, and trailer tongue weight. A CAT scale would help with that, as mentioned.
What you can tow is limited based on a number of ratings. It is the lowest of any ratings defined by the vehicle manufacturer that should not be exceeded. More details about your truck would help. Year/model/engine/trans/axle and if 2006+ the as equipped payload per the tire and loading sticker.