We normally use 'start' for the initial process and then 'run' for the everyday management after the start.
You can use 'create' if you don't want to repeatedly say 'start'. People will understand what you mean. Though a better alternative for 'start', in this context, is 'found'.
You shouldn't use 'settle' in this context. We use this mainly for when a person moves to live in another country. Perhaps you meant 'set up'...you can this as an alternative to 'start', and normally is about the complete process. For example "It takes time to set up a new business."