Accommodation - UK Open Riichi Tournament 2016
Cambridge is a tourist city, and so can be quite expensive to stay in. Because of this, however, there are also plenty of hotels. I would recommend using a hotel search engine if you want to see what is available. Website. The rooms will probably be a bit spartan, but the breakfasts are usually excellent, and it is a bit cheaper than a hotel. If that is still a bit pricy for you, you could try the Cambridge Youth Hostel. Which is near to the train station.
Venue - UK Open Riichi Tournament 2016
This is the easiest (and quickest) approach. Stansted Airport is about 40 minutes from Cambridge by direct train to Cambridge train station (see below for information about how to get to the venue from the station). This is a slightly more complicated journey to Cambridge train station, but Gatwick is also about 2 hours from Cambridge by train. There are plenty of different routes, and I would recommend asking Google Maps. What the best one happens to be when you are arriving. There are a few parking spa...