Is it true that there is a male and female plant, and if you don't have both of them in your asparagus bed then you won't get spears?
No. Asparagus is a dioecious plant, meaning that male and female flowers occur on separate plants, but this is only important if you want to produce your own seed. Here is an article on planting an asparagus bed: https://www.gardeningknowhow.com/edible/vegetables/asparagus/growing-asparagus.htm
and in case you're interested, some info on propagating asparagus: https://www.gardeningknowhow.com/edible/vegetables/asparagus/propagating-asparagus-plants.htm