Please help me!Which one is correct？and why?

[Harry12345]

Which one is correct？and why? Thank you!

1 I'm going to have a surprise party for Lana.
2 I'm going to have a surprising party for Lana.

 

[MASM]

Which one is correct？and why? Thank you!

1 I'm going to have a surprise party for Lana.
2 I'm going to have a surprising party for Lana.

If you mean that Lana doesn't know anything about the party, you should use "a surprise party".

But if you are just defining the party (which would be surprising for Lana for a particular reason) then, you'd use "a surprising party".

Although, I think you might mean the first one