I have never done any of these things in my time in the Fandom community, and I am extremely confused as to why this happened. I was block at 23:29, on July 21, 2017, even though I was not even active on Fandom wikia. I don't even know what page i "vandalised/spammed" on. If you're wondering what wikia it is, it is the Club Penguin Rewritten wikia.
The reason you gave sounds like someone else has used your IP address before you and got it blocked for being disruptive. If you are no longer blocked, then your IP has changed since and doesn't affect you anymore.