Enjoy it, you will experience excitement, nervousness, an element of I have to land this thing when in the air and it will all be fine, in fact it is highly likely to be better than fine as all the training will kick in perfectly. Just remember that you wouldn't have been sent solo if you wern't deemed safe to do it. At the end of it, you will be the one smiling like a Cheshire cat. It is always over rather quickly, so try and get a family member or friend to take a photo or video for keep sake, if you feel that it won't put you off.
S