You should have:
Wills
Power of attorney
Life insurances - at a minimum, term assurance so that if one or other of you dies, the imortgage is paid.
Other life insurance polices - do you have any? Are they connected to your pensions and if so..
have you nominated the death in service beneficiaries?
Pensions statements.
National insurance details.
N&I bonds.
Digital assets - bank details, ISAs, investments, savings accounts, credit cards - need to put passwords in a document, note any ingoings and outgoings.
Children's accounts?
It's the new tax year - are your tax affairs up to date?
Keys to properties. Tenancy agreements. Tenants' contact details. Their deposit/s. Contact details for managing agents if you use them.
Is your shit all cleared out? Not leaving letters from a long-lost love to be found or embarrassing photos?
Is your shit cleared out generally? not leaving a cellar full of crap stuff you meant to Ebay or throw away? If your stuff is good, but surplus to requriements, box it up and put directions on where it might sell e.g. collection of clocks, local auction house. (it took me two years to clear my late husband's stuff - he never wanted to throw anything away, and getting a big house iwth lots of storage didn't help!)
That should keep you busy, OP! Good luck - it's not morbid, just sensible at any point to get organised. The alternative is to assume you are immortal, and see how far that gets you...