To dream that you are at a sleepover party, suggests that you need to socialize more and create deeper friendships with people.
If the sleepover party was fun, social plans that you make now will bring you much happiness.
If the party was bad, this indicates that you are unsure of your social skills.
If you see other people sleeping in your dream, you may not be alert or informed about a particular situation in your waking life.
[1]