Give me all your metro park n ride bus to metro rail tips please

We will be using a metro park n ride to get to a metro rail and taking that to our final destination later this week. What tips do you have for a novice metro user? I know that the metro park n ride bus ticket will work for 3 hrs for other metro transportation but I don’t understand how that works, does my ticket stay on the app and I just keep scanning it? Can anyone who’s done that type of ride give me some input as to what I should expect and how it works? Thanks!