To register for a new student account please go to the link here and fill out the form following your teachers instructions
Go to this link and select the sign in button in the top corner.
Once you have signed in, select the 'my account' option under your name in the top right corner of the screen.
On the left select subscriptions and check what account type you have. You should have a student account.
Mine is an Educator account. Yours should say student
If you account is not a student account and there is a button that allows you to 'renew' then you should click that button. If there is not a 'renew' button then you will need to click the link above ☝️