There gives instructions on how to hand-pollinate plants:
https://www.zetatalk.com/food/tfood09s.htm
I would recommend that you identify the specific types of squash before you pollinate them, because they are all cross-fertile. It won't make any difference in the fruit you get this year, but if you plan to save the seeds to plant next year, and the squash have cross-pollinated, you could get some fairly odd fruit next year. But that might be an adventure!
