What are some great profitable types of services someone can start a consultancy service with solo, and later grow?

Can anyone think of examples of a service you could start by yourself and charge little and as time goes by it can grow? Im ONLY interested in a service where I get paid for thee work I do. I have kids to feed. I cant do a service where I do nothing now and hope to hit the lottery in 8 months. Im thinjking things like - Video Editing - Instagram Marketing - Web Development - Build Shopify Stores - Write blogs and articles for small businesses etc I want to start something and a year from now think "That was a good choice, its growing and profitable" not "Oh why did I pick THAT topic, were barely making a profit", thanks