There are two switches, one is auto-hold, one is the handbrake. If you turn the auto-hold ON it will activate and de-activate the handbrake for you. It takes a while to get comfortable with the auto-hold but it really works well.
If you don't want to use auto-hold (and some people don't like it), it's perfectly OK to press the handbrake switch to hold the car and then simply accelerate away - the handbrake will automatically release. However you will have to re-apply it if you are simply creeping up to a junction and need to stop again.
I know it may seem silly, but try reading the manual on this subject.