Its really early in the year for courgettes to be in flower, mine are still a couple of weeks off being planted out and then I would'nt expect any fruit until late June, early July. The first flush of flowers is often male so wont bear fruit and if the weather is still cold pollination can be a bit hit and miss.
Paula............you seem somewhat early if your Courgettes are forming flowers now......if your plants are healthy, I wouldn't worry..............not all the flowers will produce fruit..............you often get plenty of flowers first ,,,,,,,,,,,,then you get the ones which will form fruit
Cucumbers, you remove the male flowers.
Courgettes can be hand pollinated if necessary, for example in a polytunnel.
Ah yes, they are the ones where I need to pick the flower off and take it the lady flower to play and make baby courgettes
Many Thanks for your replies