If you have a hard time sleeping at night, should you nap during the day? This is a tough question. There are arguments on both sides.
Naps can be refreshing. And if you are not sleeping at night, you have to get your sleep any which way you can.
We build up sleep pressure during the day so that you end up sleeping at night. If you nap, you reduce this sleep pressure and make it even harder to sleep at night.
In this podcast, Ameer Rosic says that if you have to nap, do so for no more than 20 minutes.
John Bergman (see video) and Dr. Mark Hyman (see video) both says not to nap. Instead have regular sleeping time every day.
From an evolutionary point of view, human animals living in the wild do not nap during the day. If they did, they would have gotten eaten by a wild animal or something. So my opinion is to try not to nap if you can help it.