How do I know if a company I see on the internet is legitimate?

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I want to do an intensive driving course that cost around £600. I want to be sure that the company is not a scam and I will get what I paid for so is there a like free government website to check if the company is real or a phone number I can call?

Or if any one know how to do it and can give me the answers, the website is: http://www.surepassdrivingschool.com/

How do I know if a company I see on the internet is legitimate?