We're there next week and plan to go to a game.
I've tried to book tickets online before without success, but I've been told you can get tickets at the stadium on match days, also if you speak to the reps at the hotel they often have tickets for games, my son managed to go the the Mallorca v Real Madrid game a couple of years ago this way, and this game is always a sell out.
The ground is easy to find, you can see the stadium from the Palma ring round which you will come to as you approach from Alcudia.
I imagine parking could be a bit tricky, it is in this country at Premier league games so I expect it to be the same in Palma, we're getting in to the city early and parking up, then making our way to the ground from there.