Ah, the vbPlaza is the place, where you can buy stuff, bank your money, and other stuff. Just click on the vbPlaza menu, and have a look around. As for the points, they are money, which you can earn by posting and making thread, then you use the points to buy stuff.
As for the bank: Read these two thread:
The Bank (Last warning)
Hope that helps. Those two thread explain mostly everything about bank, and please don't ask questions dealing with bank, thereafter.