Is parking in the structure next to this building? Most stressful thing, parking. But I want to visit in person once.

Yes, there is a parking structure next to this building. I've gone twice during the week and parking is free (no parking attendant) and there was plenty of parking.

Went on a Saturday around 5pm and there was plenty of parking

You mostly park inside, so it would depend on how busy the building is overall. Most of the time, parking is available inside