Some flowers are boys, some flowers are girls (A single vine has both). Sometimes it takes a few tries for them to be blooming at the same time to make baby squash. Don't give up!!
Do not pinch it. I don't feed mine. I start with the proper nutrients at the beginning of the summer and just let them go. I think you can side dress them with compost if you feel the need, but if they are doing fine, they should fruit.

Ther are a lot of folks that consider squash blossoms a delicacy and are looking for varieties that put off larger numbers of male bloosoms.

Here is a link that might be useful: Squash Blossom Recipes