With a Essential Subscription : You can follow 5 players/Teams.
With a Premium Subscription : Follow unlimited players/teams.
When you follow players, you can choose what type of notifications you receive. This is specific to each player.
Go to "Followed Players" or on the player's profile and click on the Bell.
Or click on More, Followed Players/Teams.
This will give you the options for notifications you want to receive.
Followed Players area: Click on the bell.
On the Player Profile area: Click on the bell
In the Bell area: Choose the notifications you want to receive.
If you want to "Unfollow" a player. Click on the Bell and click on Unfollow player.