Hi L lyluk2023,
You only need to register as self employed.
You have not set up a limited company, so do not need to register for Corporation Tax
As you do not have any employees, you do not need to register for PAYE for employers.
You can always revisit these option in the future, should you need to take on employees or grow beyond being a sole trader.
Please see here for further help.
What a sole trader is
Thank you.