Depending on the chosen contract duration, your contract renews either 1 month or 12 / 24 months after the initial order. You can check these details on your invoice.
Your contract renews by the same term automatically, provided you do not cancel prior to renewal.
Hint: If you'd like to have a look at previous invoices, you can simply find them in your dashboard. Click on Plan & Billing on the very left to get to the respective section.