From what I've generally heard, the confirmation email usually comes through within a day or two, but it's worth checking your spam or junk folder first since a few people mentioned it landed there. The email itself should contain the instructions for collection at the Expo, so once you have it, you just show it as proof at the collection point, no need to print, your phone screen is fine. If it takes longer than expected, I'd just drop them a quick email at support@mummysmarket.com.sg directly, as that seems to be the most reliable way to get a response. Overall it sounds quite straightforward for first-timers, so don't worry too much!