Liability Insurance for 14 year old

Hmmm. Your problem is compounded by the fact that at 14 I'm not sure you can legally enter into a contract for insurance or anything else!

My usual advice would be to find an insurance broker, but I think you're also going to need to find a friendly adult to enter into the contract, with you declared as doing the work. I'm afraid at 14 you may be high risk ...

Plus mobile car cleaner: do you have a licence for disposing of the waste water? You're not supposed to just throw it down a domestic drain. If you search (I'm too hot ...) I'm sure there's a thread about a car cleaning business.

But however you're trying to make money, you absolutely HAVE to keep track of both your income and expenditure. You may think you're not liable to pay tax, and almost certainly you're not, but that's only because you won't make enough profit. There's no lower age limit on a tax liability, it's all down to taxable income. Plus, you don't know until you've done that whether your business is viable.

Excel spreadsheet: the following columns
Date Who / What Money in Money out Balance

So the first rows might read

7/7/18 Startup funds £20
8/7/18 Cleaning materials £10 £10
9/7/18 Mrs Smith's merc £50 £40

Don't know if that helps at all ...