When your order is shipped you will receive and email with tracking information so that you can follow its progress. This email contains a tracking number and the name of the delivery company.
If this is not in your inbox please check the Junk Mail or Spam folder, as sometimes it will be sent there.
You can use the tracking number in your email to track your order on one of these websites:
In the UK:
Royal Mail (rm): https://www.royalmail.com/track-your-item
DPD UK: https://track.dpd.co.uk/
In the EU:
DPD EU: https://www.dpd.com/hr/en/receiving-parcels/parcel-tracking/