Can you explain to me which is correct?
1) I never forget to have this party.
2) I will never forget to have this party.
Neither, Snow Lau. What you want to say, I think, is:
'I will never forget having this party' (if it is still in progress) or 'I will never forget having had this/that party' (if it has finished).
I will never forget having this party.
Remember to do = remember first, do second
Remember doing = do first, then remember
Forget is the same