You can manage your offers by clicking on your account icon on the top left-hand side of the page to open the drop-down menu. Click on the "My Offers" section.
On this page, you will see everything related to your offers. Select the "Received" tab to see the offers that have been made by other collectors on the Moments that you own. Or select the "Submitted" tab to see the offers you have made on other collector's Moments.
If you have offers in your account that you no longer wish to see, you can hide them directly on your Offers page. Head over to your Offers page and click your 'Received' Offers tab. Once you're there, select the Offer that you no longer wish to see and hit the three dots on the far right-hand side to hide the Offer.
If you'd like to unhide the offer that you've hidden, you'll need to head back to your 'Received' Offers tab. You'll need to toggle the 'Include Hidden Offers' in order to see the offers that you've hidden. From there, select the three dots on the far right-hand side of the offer and click 'Unhide'.