I’m sorry man, I know much it sucks to have to deal with this stuff. My dad died suddenly in January of last year. No will, no nothing. I’m the oldest, so I was considered the executor. Just call the companies and tell them your situation. They are all usually pretty understanding and willing to help you out in any way. I personally didn’t use a lawyer, but I had a lot of family help.
On a side note, make sure you give yourself time to grieve. You’ll get so caught up in paperwork, that sometimes you forget to be human and grieve.