I started my own business when I retired at 60.
Without doubt the best way to 'learn the rules' ie what not to do as much as what you should do is to seek advice from www.wirralbiz.biz
- or do as I did and just call into their place in Egerton House on Tower Road.
That is the new name for what i knew as Mersyside Enterprise
If you go on one of their courses (couple of days a week over 4 weeks - GREAT fun they are) you will learn about creating a Business Plan, book keeping/ accounts, how to handle tax / NI, Advertising dos and donts, raising capital and lots of other stuff. If they think your Business Plan has merit there is a grant to help you get started. When I did their course the grant was around £1800 paid in chunks over 2 years. They keep tabs on you over those 2 years ie inspect the books etc before the next chunk of money is paid. Things may have changed a lot since I started with them 8 years ago - but I suspect not a lot
One important point - you must NOT have started the business before you start with them. I think that is for legal/ tax reasons