Your licence key and instructions appear in the details of your order rather than arriving by post. Delivery is normally quick, can take a little longer at weekends and on public holidays, and never takes more than 24 hours. Softzone also has a short video showing where to find your key.
Some licences come with their own conditions, which are marked in the product name. An ESD licence starts its term on the day you download it, has to be activated on all your devices within five days of purchase, and can't be reactivated if you reinstall the software or format your computer. A VPN licence comes from another country and is activated using the VPN software Softzone explains in the instructions. All other licences start when you first activate them and can normally be reactivated, for example when you change computer.
Once a licence has been delivered, it can't be returned or exchanged, because the code can't be sold again. Read the product description carefully before you pay, and use the technical support page if you get stuck during installation.