Besides what others have answered, I'd consider to use a tool like ChatGPT to get started. I just asked it for competitors of anatomy.app and for "sites / apps targeted at medical students looking to learn anatomy" and it gave me a good and comprehensive answer in just a couple of minutes :)

This depends on your technical background. The majority of bug bounties are focused on finding technical vulnerabilities, and for that, you need to have a good level of technical knowledge. My suggestion would be that you start by learning about Penetration Testing, and then pick a technical topic where you want to specialise (web, database, etc).

This completely depends on your type of business, your current sales channels and your target customers. It's not the same to improve your workflows and scalability if you are selling shoes in retail, a software as a service online, or you are selling something else through a partners network. If your business is in the IT world, happy to help you with this in a more tailored way to your business.