Wildcard's setting is in constant flux (hence the name), but don't let that intimidate you.
The world's structure is mostly as it is today, and technology hasn't leapt forward so strongly that it's hard to grasp. In fact, you'll be fine pretending it is today for most part, though the world is set 43 years in the future.
We keep an encyclopaedia of current player knowledge, but that's quite in-depth. You don't need to know more than a fraction of that at most - unless there is something specific you're looking for, in which case the encyclopaedia is a good place to start. Wondering about the Lunar and Martian colonies? That's where you'd find it. Wondering about the political stances of country X? The encyclopaedia is your drug. You get the point.
The most notable things you should know about the Wildcard universe are these points:
- Internet - at least all parts of it even vaguely entertaining as opposed to purely functional - has become immersive virtual reality.
- Europe has merged into a single country and has become the most important economic and political force along with China.
- A nation called Dark Arcadia sits in the Atlantic ocean as an artificial island, claiming meritocracy, frequently accused of being a dictatorship, loathed by the majority of people for declining to sign human rights treaties. (That means you really shouldn't have your character think otherwise unless you have a very good reason. This is a major source of prejudice in the world of Crimson Feather. If you sympathise with Dark Arcadia, chances are you're an outcast yourself. A proper outcast, okay? Okay.)
- After Europe and China, Japan, India and the US are the major global players, with India having increased in importance and the other two having dropped.
(The rest of the world is pretty much the same as it is today, unless we decide otherwise at some point.)
The background plot of Wildcard is the classic cyberpunk concept of 'neurally connected and trapped in virtual reality'. A large chunk of the Wildcard roleplay will happen on a single server on the 'net, where people struggle to find a way back offline.
In effect, for your character, this means that almost without a doubt, your character is human, but equally almost without a doubt has internet access and something called a 'default avatar' - their online representation. You'll want to describe both.
Exceptions are characters without internet (you'd just give them an offline appearance), or sentient programs called Puppets (which obviously would have neither a means to connect to the internet, where they live, nor an offline identity).
(If you want some further guidelines, we have a writ about the atmosphere we try to maintain.)