Help with pallet weight?

So I’m working on sending my first pallet in for FBA, and I see it’s asking for a weight, how can I calculate the weight of the pallet? Could I guess like 50 pounds for the pallet weight and just add the product and box weight? I don’t have a scale for this and don’t know how id weigh it. Not sending anything crazy just about 20 things on a pallet

Also for the labels I put on the pallet boxes I just put one on each box facing the outside of pallet right?