Welcome CarolynFH!
Also different groups of people may offer a challenge that people will commit to and they'll check in with each other on a specific thread. For example, a few weeks ago on the Monday night LIVE WISH chat, they were discussing exercise (or the lack thereof) and decided to commit to their individual programs and check in with each other to be held accountable. So that's why you'll see a "WISH chatters" thread. You are ALWAYS welcome to join in on any of these at any time (in other words, you don't have to be there at the start of any one challenge).
You'll find lots of support here, it's a great bunch of losers!