No it's bad practise and will cause you to fail the test. It will also damage the brakes and may also stall the engine. Listen you your instructor and follow what he says. Forget any preconceived ideas.

only time you would need one foot on brake and one on gas would be if you were driving an automatic and want to be able to kick your brakes in faster (by about a second) for a little more control in performance driving (which you're not doing). even in this case, you never press both at the same time as you will wear out your brakes faster and waste fuel in the process.

You use the same foot for the accelerator and the brake. So there is no reason to be pushing them both at the same time.

Your other foot only controls the clutch.

Now if you did manage to push the brake and gas at the same time you will just wear the brakes faster. If you kept doing it, they would eventually burn out.

But there is reason to be doing this. If you want to go faster, you push the gas pedal. If you want to go slower, you push the brake pedal. There is no scenario in regular driving that would involve pushing both.

That Koala's smart.Listen to it.

Will pressing the Brake and Accelerator at the same time damage your clutch

the reason I'm asking is because I'm going to start my first driving lesson tomorrow and i wanted to know so it doesn't happen