Q: Stop Following Content

Follow the instructions here >  Learn how to manage your subscriptions

Any luck ? If you need visual reference tap following on the page shown in the screenshot.

Carolyn's link is VERY appropriate to learn all about managing your content.

IMHO, you always want to follow threads in which you participate, so turning off ALL notifications is not what you want to do.

Simplest answer to your direct question is:

• go here > iTunes for Windows
• Choose this button
  
• So that is is in this state of NOT following
  

That's it.

Method 2.

Go to your Bio page. Tap communities.

Tap the gogged wheel under Actions. Tap following.

sorry