Further read

Private business/Company
Set up a business (gov webpage)
Running a limited Company (gov webpage)

Sole Trader
Set up as a sole trader (gov webpage)
Community Interest Company (CIC)
Set up a social enterprise (gov webpage)
How to form a CIC (gov website)
CICs: frequently asked questions (gov leaflet)
webinar Thinking of starting a Community Interest Company – find out how

Unincorporated charity/group

What are the main differences between the charitable structures? (Cultural Governance Alliance)
Charitable Incorporated Organisation (CIO) and charity
Set up a charity: step by step (gov webpage)
Setting up a charity: model governing documents (gov webpage)
Charity reporting and accounting: the essentials (gov webpage)
Payments to charity trustees: what the rules are (gov webpage)