(UK) Advice on becoming Self-Employed

Thinking of going self-employed…….help!!!!!

I would really like to set up my own small (just me) therapy & coaching business. I’m currently in a full time job, which I will have to give up…..I am a single parent & receive a top up from Universal Credit - so I’m not sure how that works???
This is all a bit scary as I’m not sure the best way to go about it - any advice would be very much appreciated!
My plan is to hire a room above an existing business such as a hairdressers/salon/health club. I’m trained and insured so my ongoing outgoings would be the room hire, insurance & stationery/sundries…….
I have no clue whether Limited or Sole Trader is better, how to go about Tax/NI…..should I get a website? etc……..etc……..
I’m grateful for any help……Thank you