Jun 22, 2019 - 3:44 PM
Welcome to MySwissAlps, Deb!
The train station itself won't have waiting lines. The valley station of the Titlis cable cars can have long queues in August though, as it's tourist high season. You can generally beat the crowds by starting off early,, but if you're heading for Titlis on the day of your inbound trip from Zurich you'll probably won't get there any earlier than the (late) afternoon.
You can get your tickets online in advance or down at the valley station: myswissalps.com/titlis /tickets. You'll find information on costs there too, e.g. by using the link under "More information". Will you be using a rail pass that provides discounts?