Welcome to the team JT!
There are several projects that a WU can come from, some go quickly, some take quite a long time. With 2GB, there shouldn't be a problem accepting large projects (they can be up to 150MB is size) if you want.
For CPU use, folding only uses otherwise unused CPU time.
Since it seems you are using the windows graphic client, you may need to close the program while you are running 3D apps such as games.
To use both cores, add a console client or perhaps go to the beta SMP client (although I'd suggest holding off on the SMP client until the new release as it is quite beta)