Andy...in retrospect, I found the first lesson very hard too...it was like information overload with an alien driving technique..and the instructor harping on at you...
If you remember the observations, double blind spots, and follow the speed limits, you will be fine...you can drive after all...don't worry about changing down 3rd, 2nd, 1st etc, using a bit of throttle as you take off...I did those during the test when I thought I had failed and he didn't mark me down...I thought that "eco safe" driving mode was ridiculous...however if you just drive normally you won't fail...after all, everyone over about 30 drives as we do...
Also, I should add, during my test I was asked to do two bits of independent driving with maps that didn't even slightly resemble the real road...don't be afraid to ask "next right" etc.
You'll be fine Andy