Travelling from vienna to salzburg and munich by train. What tickets to buy?

My friend and I will be flying in to Vienna, staying for 2 days then travelling to Salzburg for another 2 days, before moving on to Munich. We are intending to take the train. Since both of us are under 26, we are wondering if we can buy the VORTEILScard since we are both not Austrian citizens. Also, there seems to be an Einfach-Raus-Ticket ticket for groups, but I’m not sure how it works?

thanks!