worm farms are easy, all i did was build a big planter box, split it down the middle, half for plants, half for the worm farm, collected worms from around my place, put some vegis in the soil and covered it with wood and burlap, dunno why but worms love burlap, and everytime i need a worm i just pick up the burlap and bam worms
make sure you dont press the dirt down, keep it loose so they can move about easily