(from the USA side of the pond)
I agree with Nigel.
Here we have LLC "Limited Lability Company". It has a tax ID number. Usually LLC is for smaller companies but have seen them at 50 million. From the outside the size of a LLC is not easy to see. I set up a website that makes the company look like it is larger than it is. I work with some large companies that want me to have a WWW with email. (not gmail) They want me to register with the state. With this done they feel I am not a one man shop.
Start with LLC and Tax number, if that is all you need for now. Work on more if you need to.
Now save all your receipts. I charge the company for 50% of the internet costs, one phone, travel if it is not normal drive to work. Some people charge the company for part of the heat and electricity. I do not charge the company for part of the house. That opens up problems when you move. Most hardware and computer costs are charged to the company. Printer supplies. The point of this is pay for your printer ink with pre-taxed money for
Curly hair salon.