Incorporate as a formal film distribution company. You will need to be a recognizable legal entity in order to make deals as a film distributor.
Create a press kit that specifically outlines the kind of films you intend to distribute, your marketing and recoupment strategies, your preferred media platforms, and your industry contacts, if any. The press kit should also include mock one-sheet movie posters, and a mock distribution game plan for a single project, if you have not already bought and distributed a film. Investors want to see that you have solid knowledge of how to make money in the film business.
Contact the various media outlets you wish to work with: theaters, online, etc. Send your press kit and make them aware of the kinds of films you will be offering. It's also a good idea to find out what they are looking for.
Secure funding for your company. WIthout financial backing, you will be unable to bid for films and pay for marketing and "P & A" (prints and advertising), thus you will not be able to begin your business. Funding can come via equity investments, personal or bank loans, or lines of credit.
Attend smaller film festivals and screenings. Most of the films at larger festivals like Sundance, Toronto, or the NY Film Festival are too high-profile and expensive for a new distributor and most established filmmakers are not going to trust a start-up company with their film. Try the smaller festivals to unearth new, affordable talent and create relationships with producers and filmmakers.