OP I read somewhere that I should register the name as a dormant company to protect the money - I have no idea what that means. You can't register your BUSINESS as a company, dormant or otherwise, because you're a BUSINESS not a company! Honestly, there are very different things.
Also, I have no idea how registering a dormant company 'protects' money. That sounds potentially like some very dodgy website. But I'm absolutely no expert.
I agree with Siarie it sounds like you need to do a bit more research in to how you want your business to run.
Most accountants will come and see you for a free intro meeting and give you some helpful insights.
If you want the easy life, sole trader is probably best. The money you earn is yours, do you your annual self assessment and you pay income tax on it. And it's easy to manage without a book keeper or accountant. End of.
A ltd company will save you money on tax. However you have a lot more paper work to do (or your accountant does), companies house to deal with, PAYE, NIC, corporation tax, director's dividends and your own self assessments. It's not the easy option.
It really is down to how much you're planning on earning, how much tax you want to save yourself and how difficult or easy you want running your business to be.