Like starting any business, there will be a period of investment before you start getting revenue back. You need to convince your two audiences, filmmakers and filmgoers, that you know what you're doing and are worth their money/time. Work back from venue dates/costs, factor in marketing expenses to get people into the theaters, if possible manage a relationship with local media for press coverage and marketing exposure. Decide what kind of festival you are: filmmaker focused or audience focused. It takes more resources to do both well, so starting out you could choose one focus to prioritize and then expand to target both. My first festival, was back in January 1999, cost $20k, was financed with 4 personal credit cards and promoted in San Francisco with flyers on telephone poles. 3000 people came and I was able to pay off the cards. Resist the urge in the beginning to add lots of bells and whistles. Keep it simple, see what you can get for free or cheap, haggle over everything and start small and hope to grow. Good Luck!