Ducks in a row information -
Get information for both if possible, if you can't access his then get bank names. If you know who the solicitor can request further details so the who can be important.
Bank accounts, savings, investments, bit coins, pensions (all of them), expensive hobby equipment, cars, bikes, boats, caravans and finally housing. If you own your house get one or two estate agents in to value it. Find out how much mortgage is left and work out the equity.
Put your marriage and birth certificates and any passports in a safe place.
Start decluttering the house under the pretence of spring cleaning and get the most important jobs done to ensure a speedy sale once on the market.
Put anything of sentimental value elsewhere, such as photographs you want to keep or anything breakable such as Great Aunt Mary's glass ornaments.
Start looking at housing on rightmove. Tweak the settings for location, bedrooms, prices and the tweak your expectations again and again, and probably again.
Contact a couple of solicitors to find out how much they cost and make a one off appointment.
I'm sure there's more but it's a start. Oh, look at Form E on gov,uk website. Good luck.