CVTs operate slightly differently to torque converter automatics. Typically they do not 'creep' - that is move forward when you release the footbrake and the gearbox is in Drive, but some manufacturers have engineered in this feature so they are more similar to conventional automatics in how they drive. There is a very small degree of wasted energy and potential wear if you hold the car on the footbrake and in Drive, but unless you do this for extended periods on every journey it will not cause problems.

You should hold the car on the footbrake in the same way that you would with a manual gearbox - for momentary stops. If you are going to be stationary for more than a few seconds you should engage the handbrake and ideally shift into Park so that the gearbox is locked. This is the safer option as it stops the wheels turning should you be hit by another car, and also means you can release the footbrake to avoid dazzling drivers behind you - this is explained in Rule 114 of the Highway Code. Although this means the potential for a short delay when pulling away, good anticipation and practice will allow you to shift from Park efficiently - you also have the option of shifting to Neutral and using the handbrake, which means a shorter shift into Drive.