Feed them right away. When they are hungry they'll go to the food. Do pocket feeding. Put a little bit 1/4 cup to start say, in a corner of the bin and cover with dry newspaper. Check it again in a couple days and see if they're eating/eaten it.

If you chop, freeze and thaw the food, it will be eaten much quicker than putting raw, hard food in. It takes time for the food to break down to where the worms can enjoy it.

Keep them all in one bin for now, not 3. I've read in http://oacc.info/DOCs/Vermiculture_FarmersManual_gm.pdf that if the worm density is less than 1/2 lb per square foot, they won't reproduce well. (And > 1lb/ft2 also diminishes mating.)

Mix the dirt they are already in with moist shredded newspaper, put food on top of that in one corner, and then top with shredded newspaper. There should be cocoons in the dirt, so don't throw it all out. If you've got way too much dirt for your 300 worms, let the unused dirt sit (moist) for 2 months or more and then move the babies over with the rest of the 'kids.' I'm with jasdip. At least in the beginning, freeze and thaw the food to get things started right.