Check out your local library. Many offer space for free or for a small charge. For example, at the time of this writing, the local library here charges $75 for 4 hours on a pay-as-you-go for profit basis but will let you use their facilities for free (with 4-5 months minimum advance notice) if you are doing it as a community service.
The reason for the advanced notice is because they will even do free advertizing in the city's recreation guide and website and put up posters in the libraries for you. They will also manage registrations for you.
Things to consider in addition to marketing your events could include:
-- Do you need to supply your own audio/visual equipment (TV, projector, screen, speakers, DVD player or computer, etc)?
-- How many people can the facility accommodate?
-- Do they have an option to just have chairs or is it a permanent installation with tables -- and which do you need?
-- Do you have a backup plan in case there is an unexpected technology failure?
-- Are you limited to the library's normal business hours?
-- How much time can you have?
-- How far in advance do you need to book the facilities?
-- Are you just presenting the film or will you need to allocate additional time for pre and post film discussion and/or questions and answers?
-- Will you be sending people home with some handouts which will contain your contact information? Does the library have any restrictions about doing this?
A few other options for possible venues…
-- Conference rooms at funeral homes
-- Church halls
-- Hotel rooms
-- Community centres
-- Condo/Apartment party rooms
-- Business partner (like a restaurant, especially quiet times)
Have some other ideas? Share them in the comments below.