The website of t-l (“Public Transport Organization of Lausanne”) has the timeschedules for all the buses and the metro lines. It also provides information about the tickets. Unfortunately it’s only in French but looking at the map, will solve all your problems.
In the website you can find the time schedules for all the lines and all the stops/stations (and they are very accuracy, so don’t be late). The schedule is different for the weekdays, Saturdays and Sundays and for the public holidays (or the university holidays for metro m1).
In all the stops you can find a ticket machine. In some of them you can only buy with tickets with coin, not with bills or credit card. So it’s good to have some coins with you or to buy a “galaxy” card.
There are also weekly/monthly/annual cards that are very convenient. You can buy one either at the cff stops (Lausanne-Gare, Renens-Gare), or at the t-l center at Lausanne-Flon. There is also a cff office inside EPFL where you can also buy the card. For the renew of your card, you can use the machines at Lausanne-Gare or at Lausanne-Flon. However, if you have the paper version of the card, you need to go to the office every time.
There is also a very useful app for smartphones that gives real-time time schedules for all the buses/metros and for every stop.