stand

Hello all, I need to attach this plate to one of my light stands. What accessory do I need for it? I'm trying to make a portable shooting surface. I've attached pictures of the plate and the tripod I'm trying to link up. Thank you in advanced.

Looking for ideas or recommendations for light stand weights. What do you use , buy or make for yourself ? I have seen some striped sand bags on Amazon but have seen no sample in real life, the bright stripe trip hazard colouring appeals. Looking for about 6, so not looking at expensive...