If you're on the Artist Plan, you can subscribe to 1, 2 or 3 artists total - you select this number when you create your account. Subscribing to an artist allows you to see pretty much all of the information on their artist profile page.
To check which artists you're subscribed to, or to subscribe to them if you're not connected yet, click the vertical three-dot menu (top right of any page), go to Account Settings and look under the Subscriptions section:
If you're on the Artist Plan but not yet subscribed to your artists, you'll see the Add Artist(s) to Subscription section. Use the Search Artists search bar to look for the artist(s) you want to subscribe to, up to the number in your Account Type (e.g. 2 Artists):
Once you have searched for and selected the artist(s) you want to subscribe to, your selections will show up beneath the search bar:
Don't forget to click the navy blue Subscribe button to the right and then you're done! The Add Artist(s) to Subscription section will change into the Subscribed Artist(s) section and you can now go to the artist(s)' profile page to see more information about them: