Investors will want three things from you - a business plan, an exit strategy and at least 70% ownership of your startup (probably more actually)
Investors may not want you in the startup company in the role that you had in mind. ("What do you mean I can't be CEO of my own startup?")
Business incubators offer 'free' seeding money, but you often won't get it until 1 or maybe even 2 years after incubation starts.
A good business incubator will bluntly tell you what you need to do/change to make your startup successful.
There is such a thing as incubator 'sluts' - companies that literally bounce from one incubator to the next, barely scraping by on the seed money from each.
Personally, if I were to launch a software startup, I'd build an MVP in my spare time and then shop around looking for investors/clients/incubators to take it to the next stage.