Just to add, the Halloween event generally doesn't start till mid-late October, since it only runs about a week and a half and always runs during Halloween, it has to start later in the month. I'd suggest waiting till at least the mid-month update (which is usually posted around the 15th) till you start keeping an eye out for it, that update may also mention how much longer till the event starts. Here are the previous Halloween event start dates;
2009: October 22
2010: October 19
2011: October 17
2012: October 20
2013: October 25
2014: October 17
2015: October 23
2016: October 21
2017: October 21
2018: October 20
2019: October 19
2020: October 23
2021: October 23
2022: October 21
2023: October 21
If you participated in the Easter or Summer event in the past year, the Halloween event works the same way, there will be banners to click to get tokens for the event which you can get every 20 min, and new free pets/items and token trade-ins are made available each day of the event.
Once it starts there will also be event threads that go up in the
event board which will include a questions thread that has an FAQ on the event and provides a place to ask questions concerning the event if you are having trouble with any part of it.