Lone parent started new job what to do with these P45 forms I've received..

[Listerdieselengineswroughton]

I've been at home bringing up my family for several years. The last time I worked I had no children.

I've just recently started a new part time job beginning of January and am unsure what to do with two forms received in the post.

I've asked 'HR' - jaded ol' madam who clearly hates her job, her life, and everyone - and she just looked over her glasses at me silently, so I've no idea what that means, and was too embarrassed to probe further so walked off.

I have received a 'P45 Part 3 New Employee details for completion by new employer' and

'P45 Part 1a JobSeekers Allowance Claim Keep This Copy' which shows info for period up to end of JSA claim.

I don't know if my employer has been in touch with tax office or tax credits people or what to do with these letters. Can anyone advise?

Thankyou