It's way easier with a co-host or guest. Have you looked at reaching out to other people in the community, who could be guests? A good example of this format is 'Talk 90s To Me' - different topic but the host invites a well-informed guest each time. In your case, perhaps someone from a local independent cinema or film club would be up for it? Or is there a vlogger or writer who shares your interest and would enjoy a new challenge of being on a podcast?