A very important effort is being made at the moment to help English speaking users in the use of Siril, you will find a series of videos in English on our YouTube channel. In the same way the documentation is completely redone with the arrival of the next version of Siril, it's also produced in English and will be available soon.
Thank you for being patient, because this work takes a lot of time.
If you wish, you can even help us, because when we'll make the video tutorial, we'll need raw files ;-) and the sooner I have them, the sooner the video will be produced...
You will find the requested tutorial on our new forum https://discuss.pixls.us/t/comet-registration-tutorial/16248
, as explained on this thread: https://www.forum.siril.org/index.php/topic,253.0.html