Your flying school and instructor already trust your flying enough to allow you to take one of their aeroplanes, go flying in it, land at some other airfield, and bring the aeroplane back again - without damaging either yourself or the aeroplane - and without an instructor sitting next to you. You've already demonstrated that you can deal with normal flying, and with things that might go wrong - they wouldn't allow you to fly solo otherwise. You don't know it all (a PPL is just one step in the learning process), but you're not going to be asked to do anything you haven't done before. So there's really nothing special with the skills test - it's just that last tick in the box that will allow you to do what you've been doing already, but without an instructor looking over your shoulder each time.
Best wishes - I hope it goes well.