How Would You Make Sure There Really Is a Market For What You Sell?
Google the search query "small business ideas" and you'll find thousands of articles which will purportedly provide you with this valuable information. Truth though is while some of the business ideas listed in some of the articles are great, they won't be viable for everyone.
Before starting a business it is important that you do some research, find out if there is a market for what you'll be selling. Friends and family could be willing to buy what you sell so if you need to evaluate how profitable your business might be, don't pitch your idea to them. They'll probably motivate you to "go for it" which won't be of much use to you in the long run.
Track down your potential customers on social media or even in the real world on the streets and ask them if they would be willing to buy what you want to sell. This way, based on the information obtained you could estimate your potential sales and profits helping you decide quickly whether it will be worth it to start a particular business.