Your tracking number would have been emailed to you when your order dispatched. You can also find your tracking number from logging into your account and locating your order. If the order has shipped there will be a tracking number available.
If you opted for the UK Next Day, Expedited Tracked Shipping (worldwide) or DHL Express shipping you can track it using the following links:
Next day shipping - https://www.ukmail.com/manage-my-delivery/manage-my-delivery
Expedited Tracked Shipping - Track on your local country postage website, i.e. USPS.com, Posten.no, etc.
DPD - http://www.dpd.co.uk
DHL - http://www.dhl.com