An Adobe Stock subscription can be added to a Creative Cloud membership.
Please check the FAQ for details: Common Questions, Adobe Stock
You can check which subscriptions you have from the account management page - Adobe ID. Sign in with the Adobe ID associated with your subscription and check under Plans & Products.
In addition to Bev's response, I did check your Adobe account but right now you are not subscribed to any plan.
Let us know if you subscribe and we can help you better.