My "Participation" and"My Subscriptions" aren't correct? Why?

I went to my preferences > My Subscriptions and found threads that I didn't subscribe to. One was even in Spanish and I know I didn't subscribe to that thread. All the subscriptions were for "Pages". I wouldn't think I subscribed only to "Pages" and to all "Pages" threads.

You get subscribed to any Topic (sub-forum) [e.g. for the Pages app, if that applies] that you ‘Follow’, as well as any thread in which you click the bell icon, and automatically any thread in which you participate. Additionally, if you are a long-time member here, Apple has historically changed some topics, and grouped and ungrouped some topics in the past, which may have gotten you a subscription for which finding a match is difficult.

While this forum is intended as the English language forum, no-one has control over users (accidentally) posting in other languages. Participation in any of the other language forums may require a separate registration, and probably wouldn’t show here.

While on that page I clicked on the tab "Partipation" only to find the number of times I participated in threads but no link to any of those threads nor even a title of what those threads were. What good is knowing how many threads I have participated in if there aren't any links to go to those threads to see if there have been any updates that I missed?

There are two mentions of Participation. What you found is the basic statistics. The other one is a Filter for your subscriptions. You may have been looking for that instead.

You may want to bookmark the URL for your participated threads.