I really do get you! It's quite common for entrepreneurs to have doubts - like every other minute! 😂
To know if your idea is good for business you need to answer few questions:
1. What problem are you solving?
If an idea doesn't solve a real problem for real people, the startup won't be successful. A lot of entrepreneurs start with the solution, and by that, they risk spending lots of money and lots of time on a solution nobody needs. A problem is simply a gap in the market.
2. How are you going to solve it?
Is your solution in any way better than the rest of the solutions on the market? If it is, you might have a good chance to compete. Be sure of your business's strengths and weaknesses at all times.
3. Who are you solving the problem for?
This is your future target group. People who will be interested in using your product. The more details you will know about them, the easier is going to be to reach them.
4. How does your market look?
Is your market increasing or decreasing? Is it hard to enter? Know your market's worth, and your projective market shares.
5. How are you going to make money?
There are a lot of revenue models that you are able to use. Depending on the industry of your business you can choose subscriptions, ad-based, direct sales, rentals, and many others! What's important is to make sure your business is profitable.
When you've answered all of the questions above, there's nothing left to do but validate your idea! How so? Go ask your target group what they think of it. It's either doable by interviews or questionnaires, but make sure to present your idea as transparent as possible, so you'll be sure to get honest and accurate answers.
Good luck with it!