It's really simple...for 2018 go to this thread and make a comment. Then you will be subscribed to the thread and when anything new appears you will find it in the Subscriptions tab at the top of the page.
2018 UFO Challenge of the Month
How you choose to participate is totally up to you...some of us have lots of UFO's we feel the need to finish. You may or not wish to list them...personally I don't, it would scare the bejesus out of me! Then as you complete a finish post it to the above thread with or without a photo and happylab, our new fearless leader, will keep track of our finishes. The opening comment on the thread has more concrete suggestions...
And most of all, welcome to the group!