While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
Note: This feature may not be available in some browsers.
You go to the top toolbar of the CGN main page. Click on "Forum Rules & Terms". Follow the links to the Equipment Exchange [aka EE] rules. READ 'EM. Then follow the process outlined there to apply for EE access. Once you have been granted EE access you will be able to post your item for sale there in the appropriate forum.
Just to advise, you can not, under any circumstances post item(s) for sale outside of the EE.