At a high level you would have to do the following to start a startup. The order of some of these tasks may differ in each startup.
- Have or find a large enough problem to solve.
- Find a solution to the problem.
- Do market research, interview potential users, to find initial product market fit.
- Find co-founders who believe in your idea.
- Setup core equity structure and vesting plans for founders & future employees.
- Build your core team (resources with diverse skill set).
- Work part time or full time on your new venture.
- Acquire seed funds from Angel investors or boost strap yourself.
- Incorporate your company and complete any legal requirement to run your company.
- Develop a MVP (Minimal Viable Product)
- Launch your MVP, test and get feedback.
- Build next features based on feedback
- Go for funding if bootstrap funds not enough to support operations.
- Market and promote your product/service.
- Acquire Customers.
- Grow your business and company.
*Startup takes time to succeed, so make sure you are committed to see it through.