Just give them a ring. Email is nice and convinient, but things get lost easier on servers than they do in the post. Plus if you ring they aint going to say no, unless they are really well booked for a while...
As for a passport, dont worry about it, when i had my trial lesson, they never asked for any ID what so ever. I am sure that some places do take id numbers down, but i cant see this been a problem...
Give em a ring and get it booked, it will be the best thing you have ever done, but it may hit your pocket money as you will get hooked...