How to prepare?
Learn to budget properly. Look at Dave Ramsey or YNAB program. Lots of youtube videos/blogs discussing these techniques. Also CAP offer budgeting classes. Try to get to a point where you have 3 - 6 months basic living costs saved away. Pay yourself first, ie before you pay any other bills/expenses, put a chunk into an instant access savings account. It's there if you need it (eg boiler repair) but you can't fritter it. Lots of frugal living tips on MSE, eg downshifting grocery brands. Allocate your essential expenses, then give yourself an allowance for "fun" spends, like coffees, alcohol, magazines, household knickknacks, non-essential clothes etc.
Get out of debt ASAP. Throw every penny at it. On your credit cards, switch from direct debit to standing order. DDs pay the minimum amount every month and gradually decrease as you pay back the loan. SOs on the other hand are a fixed amount. The monthly repayments remain constant. Because of this it means the repayment term drops dramatically. Thread & spreadsheet on Money Matters section on here.
You don't need a zombie apocalypse stockpile, but put away a couple of boxes of basic store cupboard groceries in the attic/under stairs in case of job loss/crisis. Baked beans, tomato soup, tuna, sardines, rice, chickpeas, curry paste, UHT milk, loo roll, laundry powder, washing up liquid etc. Keep rice, flour etc in pest proof boxes. Buy cheap, but what you'd be happy to eat/use in a pinch. Just buy a few extra tins per week. This is a good investment actually as these sort of goods will be subject to inflation, and inflation is very likely to outstrip the interest rates you'd be earning in a savings account.
Look into training for other skills so you can diversify your income if you need to. Children's hairdressing, gardening, dog grooming, care work etc etc.