how do I unsubscribe to communities?

You appear to be following the ApplePay community which is the default if you post something there so you will be getting an email every time anyone posts anything there. Simply click on the "following" upper right side to "unfollow" (it will change to "follow").

And, you will want to click on your name (upper left corner), then click on Preferences and untick email notifications.

Ok, here is your page:

https://discussions.apple.com/profile/NvDan/places

and it shows that you are following the ApplePay Community. Either click on the Action Gear to click on Following which should turn that off and change into Follow. And/or, go here and do the same thing:

https://discussions.apple.com/community/apple_pay

Yours should show Following (since you are doing that) - when I go there, it offers me to Follow since I've not been to that page before.

And, when you click on your name, it should show you this type of popup window (if you are signed in):

At the bottom, you can go to various settings to change your preferences.

I think this is the document you need to read through.

https://support.apple.com/en-gb/HT202547

If you want it in another language, scroll to the boyyom of the page and click on the flag > then choose the country / language you require.