Always loved the opening parade.
Each brewery has a tall cart with women handing down free liters of beer to drink as you walked past. Must have had about 7 liters that way each year free.
You have to like crowds and learn how to get your bier, generally outside the main tent was the rule where there were picnic tables then I would wander around inside round and round.
Go during the day as evenings get very busy.

My favorite Munich fest was the stark bier fest on the Polanner Knockerberg never crowed and the beer much better