Hiya. Before you build anything get to a couple of events, take pictures, sounds sad but take a notepad and pen, talk to everyone, look at how the majority of stuff goes together, which websites do they all use to get their bits etc? The different countries and regions have different rules and common build techniques because certain materials are readily available. For example, the UK is full of plastic drill powered robots as it's what's readily available. The US is full of beetle and hobby weight stuff, and there are a few sites that sell the running gear locally to be able to put one together (wheels with the right hubs for the common motors, ESC's and batteries etc.).