I struggled getting my flowers pollinated but I did eventually get fruit. I had a fan going but apparently it wasn't enough so I would shake the plant or try to press flower to flower to get pollination going. Peppers also like heat so this time of year may be too cool.
Sadly I got an aphid infestation and since aphids seem to love peppers, I pulled the plant. Unfortunately the aphids are still winning
It could just be a pollination problem. Or your plant could be lacking in some nutrient. Any weird-ness going on with your pepper leaves or stems? Purpling, yellowing, curling, maybe stunted size?
Broccoli and cauliflower are seedlings? Thin them out when it looks like they are going to start crowding each other out for lighting.