OPF backdated and Tax Credits

Iv three questions.

Question 1
Iv just applied for OPF and have seen some people mention this being backdated - does this mean that if you have applied on time and are approved it is backdated to when they were born??

Question 2
Iv have received my p45 from work and was just enquiring about what to do about tax credits. Iv seen people mention this but dont understand what this is about. Can someone explain? Is it that I claim tax back? If so would appreciate advice on when and how.

Question 3
Also will I get a p60 from my employer next year and do I need to do anything with this?

I can answer the first one for you. It will take some time to process your OFP claim, but if it's approved, you will be entitled to payment from the date you applied.

If you're available for and seeking full-time work, you may be entitled to Jobseeker's Benefit based on your PRSI contributions. You can claim Jobseeker's while you're waiting on your OFP claim to be processed, and you might be entitled to part of your jobseeker's after your OFP claim is decided.