following the link do I just enroll for a new HH account, or do I register for an account with Infinity MileageLands first and then enroll for a new HH account?
if u just sign in with that link instead of signing up will i get the extra 1k points?
No, it's only for a new account. If you sign in with an existing one, it'll just give you the option to choose EVA Air as your partner airline to earn miles with.
This doesn't have to only be for those without accounts, I'm gonna guess that this ( https://secure3.hilton.com/en/hh/customer/account/combineAccounts.htm ) would make it applicaple even for those who already have.