Got severance, how does it affect benefits? after 12 years as a software tester

I was offered severance of 12 weeks after being let go as a software tester and I am unsure how it affects benefits. I do not usually post, so bear with me. I have a mortgage and need to plan. Who should I ask before signing?

I filed on day one anyway and reported the severance honestly. The agency decided what to do about the timing.