I just use the local trucker scales (
CAT Scale). Run through once with truck and trailer and one with just truck. First weigh will cost you $9-12, each additional weigh in a 24 hrs period will be $1-3. Have front axle on scale pad 1, rear axle on scale pad 2 and all trailer axles on scale pad 3. Then take the two weight tickets to do the math on trailer weight and tongue weight. You can also use a local dump scale or a local feed store scale but you might have to do each axle individually on those. Some states allow you to use the highway DOT scales when they are closed but check first as not all states permit this.