Lausanne sits on the main rail line between Geneva and Bern, with frequent direct trains to both (roughly 40 minutes to Geneva, 70 minutes to Bern). TGV services connect directly to Paris in about 3.5 hours.
The nearest airport is Geneva (GVA), about 45 minutes away by train. Direct trains run from the airport terminal to Lausanne's main station several times an hour.
If you are driving, Lausanne is on the A1 motorway that runs along the north shore of Lake Geneva. Parking in the centre is expensive and limited — the train is almost always the better option.