Passenger trains

Hello everyone, sorry if this has been asked before but I’m still pretty new to the game, I only have 4 trains and the east side of the map opened up and Bryson. Could someone give me any tips on running the passenger trains. I only have one train doing passenger trips right now through the available stations but then I have to change each car manually to a new train tag so I could use a different time table. This is very time consuming as it requires clicking on each car. I wanna know if there’s a quicker way to change one train between time tables or if I should be running more than one passenger train in either direction. Thanks for any help!