First, you need to contact your local county bar association, look on line, there should be an office in the San Jose area. They should have a probate referral panel. Call them and tell them you need a "modest means" or small matter lawyer to help you with a probate consultation and possibly a letter. Then meet with that person. Probably you will be charged a modest fee, but I suspect it would be quite small for a consultation. If there is a bank account in your name somewhere, you should be able to collect it with a certified death certificate and the bank's form for such purpose, or possibly with a Small Estate Affidavit.
As to the promise to be allowed to live in the house, that may be the subject of a creditor's claim, if you could substantiate the promise. Get a probate practitioner in the same county where your parent lived.