Um, it's fairly straightforward in any court, you open the door and walk in...
If it's a closed proceeding, the door will be locked or there will be a sign/person there to tell you.
There's no problem in walking in during a case, so long as you're quiet and respectful. In a lot of courts, they're constantly dealing with business, so there's no pre-defined breaks or anything.
If you want guidance as to what's on or suchlike, ask at the reception.