Father passed away suddenly. Now what?

added an NSFW tag as this is pretty heavy and could be a lot. I'm sorry if I miss some important stuff the last couple of days have been a lot.

if it matters this is based in Washington State.

my dad passed away on Monday March 23rd. he had no will.

the coroner stated he died from cirrhosis caused by extreme alcoholism, makes sense as he struggled with it for about 3 decades. he was 52 and he left behind 3 kids, me (33M) my brother (19M) and my sister (17F). he was divorced (about 20 years) and didn't have much, he lived in a townhouse and had 2 vehicles, a broken down 2000's Infiniti and a Ford f-150. both are paid off.

for reference. I've already contacted all immediate family about the death. have secured both of the cars and have notified his property owner/landlord and have informed them that we will be cleaning his place out before the end of the month.

this is my first time being in this position, and I know my dad worked for a few pretty big name companies including a Ford dealership when he was younger for a few years before he moved and worked at weyerhaeuser. he worked there for over a decade, his job ended around 2015 (could have been before that, not entirely sure.) his position was as a plant and operations supervisor and I know he had a 401k or a pension. he also most recently worked for a construction business as a shop repair technician. my question is, how do I find out if he has anything left of these retirements or 401k plans? is there a way to just plug in his social and it'll tell me if he had a retirement plan?

I'm looking at services for him and am finding that a service, even on the cheap side is going to be financially straining and anywhere from 1500 to over 6000. I understand it's not a lot of money, but, out of nowhere this kind of expense would take a lot of time to recoup and may force me to go on a payment plan or even borrow money.

I guess what I'm asking is simply what do I do next? I am sure there are lots of you out there that have had the same thing happen or have had a similar experience so I'm trying to grasp all of the things I need to do.

to clarify, this is not about me hoping my dad had some billion dollars hidden away (he didn't). this is not about me trying to get to some hidden treasure. it's simply trying to figure out a way to use any money he had in a 401k or pension to use towards cremation or a ceremony afterwards. I would like to not have to sell the f-150 to afford this because it was my grandma's first, when she died it landed to my dad and now that he's died I'd like for it to stay with me or one of my siblings as a sentimental piece.

sorry for the rant, as you could expect it's been a long 3 nights and I am hoping that getting these small things figured out now will make for an easier process for me later to be able to truly grieve.

thank you in advance for any advice you might have.