Well you're very brave taking grade 6 as your first practical exam as you're right, you do have to learn ALL the scales & arpeggios for this one. I learnt them in sections to make them easier so one week I'd learn all the majors, the next week harmonics & then finally melodics until I'd got them all done. I found arpeggios hard at first too but as everyone always says, the more you play them the better & easier they'll become. It's funny that you find the melodic scales easier than the harmonics as it's usually the other way around!

As for your pieces, I don't think many people chose Andante as their A piece so it'll be nice for the examiner to have something different to listen to.

To be honest, I don't know the other two pieces you've chosen too well but I'm sure you'll play them brilliantly in the exam!

I really hope you do well & try not to worry too much. Easier said than done I know, but try to relax as much as you can & don't think of it as an exam, just imagine you're playing for a friend or relative. Lots of people have said that eating a banana before an exam helps to calm nerves so it might be a good idea to eat one just before you leave.

The exam seems so scary especially when you're waiting to go in but once you get in there it's never as bad as you think it's going to be. They usually only last 15 mins or so so it'll be over before you know it! Good luck & let us all know how you get on.
Lisa xxx