If you’re coming from overseas, the nearest airports are either Cardiff Airport, or Bristol Airport. For international visitors, London is served by four major airports or you can fly to Manchester or Birmingham.
Cardiff Central can be reached by all major cities. For details of train times and to book tickets please see National Rail.
Cardiff is served by an excellent bus network. You will likely be staying in the city centre within walking distance of the venue but if all the conference-ing tires you out, local bus information can be found on the Cardiff Bus website.
You can find visa information on the gov.uk website.