To subscribe to the Premium or Basic plan as an individual, head over to the Purchase license page, and choose Individual License.
Then, choose either the Premium plan or the Basic plan, and choose whether you want to be billed monthly or annually. Note that the prices do not include VAT, where applicable.
After choosing your plan, fill in your contact details and click on Checkout to navigate to the payment processor. The payment processor will redirect you to a order confirmation page, which displays your license key. Your license key and billing portal link are also emailed to you after a successful order.
If you were logged in with a teacher account, your license key is now activated. If not, follow the instructions here: How to attach a license key?