Welcome:)
Here is some useful info about making treasury lists:
https://www.etsy.com/help/article/82If you will need any further assistance, please, let me know (I will check my convos regularly, just have in mind our time zone difference:), so my answer can come not right away).
"... when this becomes full and it's time to create the treasury will I be notified somehow?"
OK, I will let you know also via Etsy conversation.
I'm thinking (if you all agree) to wait one more day and if we don't have a next member on the list to start to create a collection and those 6 items everybody will add from other Etsy shop he/she likes - just pick items you would like to have in your collection. This can also be a good opportunity to have some more views to your shops from other Etsy members.
BTW, you can start even now, in some free moment, to choose some items from these 10 shops, which are already on the list, just keep your collection not visible yet and only when you are ready, you will send it online (when you edit your treasury, you will see on the upper right side those two buttoms: Everyone Only you / Draft ? ).
Tip: be sure to click "save" button very often, if you do it, even if something goes wrong with e.g. an internet connection, etc., you will not lose, what you've done until that moment.