If travelling by car, take the M11 motorway and exit at junction 12 for Cambridge. From there, follow signs to the city centre. If travelling by train, Cambridge has its own station with direct links to London, Birmingham, and various other cities. From the station, it's a short walk to the city centre. From nearby landmarks, such as Ely Cathedral, there are regular train services to Cambridge. Alternatively, there are bus services available from neighbouring towns, such as Huntingdon and St Neots.
To avoid traffic, it's best to travel to Cambridge outside of rush hour. Consider taking public transport, particularly for city centre parking, where it can be expensive and limited. If travelling by car, consider using park and ride facilities on the outskirts of the city. These provide frequent bus services which are both efficient and reasonably priced.