2. I have planted summer squash. There are lots of pretty squash blossoms! But they all fall off. Is this normal?
Do you have all of one gender of blossoms? The first ones are typically all male. You can look at them and determine the gender by looking for an immature fruit behind the female flower. The timing has to be just right, so it can be hard if you only have one plant. I would take a paint brush, find a male flower on the first morning it opens, get some pollen and pollinate the open female flowers. Do it every morning and hopefully you'll get some fruit.
I ususally let bees take care of this.

It does help to have at least two of everything you are growing. The plants do not have to be the same though i.e., one yellow, one zuchini for instance. We don't grow summer squash anymore because I am totally burnt out on it. We would have two plants and they would produce enough to feed a small village for months.