Your lettuce is a long way from making heads, Broccoli needs a lot of room and will get about a meter tall. When you cut the head it will form more, cut off all but the best two new heads or just leave them. Green caterpillars from the white cabbage moth love them. I just pick them off.

You can cut some leaves off most of your lettuce and leave only a few to make heads. If lettuce grows too slow it gets bitter. bone meal will encourage root growth so they take up more food. Don't mulch close if your ground is wet, you will get slugs. Remove lower tomato leaves so they don't touch the ground. When they set fruit cut the stems that have just leaves back about half way. Remove the branches starting in the forks or you will have a jungle. Don't remove any fruit spurs.