Octoberfest

There are some resources on the web, this is one https://oktoberfest-guide.com/oktoberfest-reservations/ I can't vouch for the info, just an example.

But the basics, first, reservations are handled by the respective tent, there is no one stop system. In April and May, they may start opening reservations, you have to act fast. Changes mean that reservations are limited, not the entire tent can be reserved, only 65-75% of the tables can be reserved now.

A reservation is really a guarantee of food and drink purchase. You must reserve a table of 10, and pay for the equivalent of 2 Mas of beer plus a half chicken (you can actually get other things, but the price is set on that. So a table reservation will run you 350-400 euro.

You do not need a table reservation, you can show up and hope to find free seats, but that would be tough opening day You will have better luck during the week.

There are tour operators that promise a seat in addition to a walking tour.

Go just before lunch before the tent is starting to fill up.

If you go around 2 p.m., you can enjoy everything and not have to deal with making a reservation. The only difference between going then and going in the evening, is fewer people and that, to us, adds to the enjoyment. Just something to consider.

All true but unfortunately not really working for the opening day.