First, go to Manage Offers > My Offers. There you will find an overview of all your offers (except the offers you already put into the archive).
How to put an offer into the archive?
You can put offers into your archive after deactivating. The "deactivate" symbol turns into an "Archive" symbol. Just click on it to send your offer in your archive.
For every active offer, you can choose the option "deactivate". If you already deactivated the offer, you can also reactivate it when you click on the turquoise button next to the red "deactivate".