Only the second one is correct. 友達は五人だけです is more polite, though. You can also say 友達は五人しかいません.
As for #1, 五友達 is ungrammatical, and you need to use いる/います instead of ある/あります for animate things.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.