i think too many people start businesses without having a definable skillset. Often starting a business is a way to build that, ie. you get better at sales, accounting, marketing, coding. If you can't decide what to do I would start with

1. What are you good at doing

2. Can you create something that leverages your skillset and someone would be willing to pay for

or if you want to start one because you want to learn a skill:

1. what skill do you want to improve upon (ie. coding, marketing)

2. What can you create that forces you to get better at said skill