If you're running a class in Washington, D.C., consider a venue that's conveniently located near a public transit hub or with ample free parking. The closer you get to downtown DC, the harder it is for attendees to park. Office buildings, coworking spaces, collaborative workspaces, and warehouses with loft spaces typically have ample lot or street parking.
You can also hold a class inside of an educational institution, like an art gallery, museum, high school, or university. These institutions not only have good parking amenities but will have projector screens, seating, microphones, and other essentials for a successful class. If your class space needs areas for people to power electronics or appliances, scout out the room beforehand to ensure the power ports work and are in the right places.
Classes can also be held in outdoor locations. Botanical gardens, urban parks, outdoor cafes, and rooftop lounges can all be the grounds for a class event, as can a vacation home, estate, or mansion. Large rental homes have the added advantage of including several different event spaces with a single rental. That makes it much easier to plan not just your class, but also a meal, social
meetups, and other events at the same time, rather than reserving multiple venues for different aspects of the event.