We found out my stepfather died last night in an accident. Do/can I light yahrzeit tonight? What prayers can I say? What can I do?

The police woke us up to inform us at 4am. I don’t know what to do in prayer. I just said the mourners Kaddish because I didn’t know what else to do prayer wise. I want to pray for him and his soul. What prayers, what do I do? I want to pray for him. I want to know his soul is in a good place.

I’m sorry if this is a dumb question. I haven’t been very active in religion since my bar mitzvah 7 years ago and Jewish youth group 3-4 years ago.