Train from Munich Airport to Salzburg

Your flight schedule to Munich might change between now and then so I'd wait until you arrive but familiarize with the schedule using the DB site
https://www.bahn.com/en

Using the English version of the site select From: Munich Airport To: Salzburg

And then the date of the Outbound journey

thank you!

You can buy a Bayern Ticket out of a vending machine at the airport train station. 27 EUR for the first person and 9 EUR for each additional person traveling with you, up to 5 traveling together. Weekdays, you must travel after 9 am, anytime weekends.

There is a regional train every hour from Munich Hbf to Salzburg. This train also stops at Munich Ostbahnhof. The S-1 train goes to Munich from the west and gets to Munich Hbf first, and the S-8 train goes to Munich from the east, so it gets to the Ostbahnhof first and you can get off there to get the regional train to Salzburg. S-1 and S-8 departures alternate, so there is a train to Munich every 10 minutes. So you can take the first available train. No reservations needed or taken.

We were there doing this in April. Download the DB Navigator app and buy from the app. There are great senior rates if that applies. The ticket machines are very moody with US credit cards without pin #'s.
I agree, buy at the station. If your flight is delayed, then you have a problem with pre-purchased tickets. Hopefully, you're coming in a day or two before the tour starts .
Safe travels!

I easily downloaded the app and looks like some senior rates will apply. Much appreciated Sam and Pat.