Marriage at PH embassy

Hello kabayan! Anyone here can help me to clarify and answer my queries about the  requirements needed for marriage in PH embassy Abu Dhabi?

Questions:

Where can I get/req for DFA auhenticated NSO and Cenomar? Should it be directly in the Philippines?

How about the DFA authenticated affidavit of parental advice? I saw the form in the PH embassy website. Can we just print it and let our parents in the philippines fill it up and then have it authenticate in DFA philippines? Or after filling it up do we need to give it to a law office first before having it authenticated by DFA?

Last is this signed joint affidavit of two witnesses. I also saw this form in PH embassy website. What to do with this? Just let my witnesses sign this form? After that do we need to take it also to a law office after having it signed?

Thank you