Maybe someone who's been recently will chime in, but if they are staying onsite, they can find out in the lobby usually. You can ask someone at the desk, I recall seeing little signs on the desk as well with park info. There is often signage at the entrance to the parks as well, regarding the parade, and nighttime shows. The best way is to use the UO app.
As far as now, I can see on the app that the Cinematic Celebration at US is scheduled for 9pm tonight. I don't believe the Hogwarts light show has restarted yet, at least I haven't seen anyone here post about it, and the app says, "Show Times not Available".
Shows, parades, character sightings etc. are still hit or miss, probably due to staffing. It seems that things are starting to open up more now in July though. I would check the app daily to see what's normally happening now.