After your two-week trial period ends you will be billed £6, and £6 every month thereafter unless you cancel or pause your subscription.
You can find the renewal date on the subscription email that was sent to you when you started your subscription.
The billing cycle is monthly from the date your two-week trial period ends, and you will be charged on the same date each month. For example, if you purchase your subscription on 17th January you will next be billed on 17th February.
If your billing date is not present in a month (say, the 31st) then the preceding date is selected (e.g. the 30th). The renewal shifts back to the original date in the next month.