Cambridge Station is located on Station Road and is a 15 minute walk from the city centre. There are normally plenty of taxis available on the rank outside the front of the station as well as buses. The main direct rail routes from Cambridge station are south to Stansted Airport (35 minutes) and London (Liverpool Street and Kings Cross Stations - Approx 1 hour) or west to Birmingham (Approx 3 hours).
Train fares are quite complicated in the UK, and if you just turn up at the station without booking a ticket you are likely to pay more than double what you need too. To get the cheapest train fares it is better to book in advance and travel during non peak times (after 9:30 am). For example the single fare from London to Cambridge can vary an amazing amount - between 19 and 31 GBP depending on whether you just turn up at the station or book online in advance.
There are two car parks at Cambridge station. For short term stays there is a pay and display car park on the station forecourt. Drivers can stop in a pay and display bay to pick up or drop off passengers without paying, but waiting for passengers is not permitted and you must stay with your vehicle at all times unless your passengers need help.
For longer term parking (if you are catching a train) there is another car park operated by NCP car parks. The car park postcode is CB1 2JW if you wish to locate it using a satnav device. The long term car park is open 24 hours a day, has 449 parking spaces and is free for the first 20 minutes. Charges after this are 7.20 GBP for train travel at peak times and 4.60 GBP off peak or 30.20 GBP for a weekly pass. See the NCP car park website for more details.
The station has a left luggage facility if you wish to leave your luggage while you explore the city and there are a number of small shops for light refreshmnets.