Ive brought some cheap items from the market but don't know how to equip them can someone help me??

You can do that by clicking the Shop located at the top of the page.
After you click the shop, you can search for your deactivated inventory that will appear at the left side with a bunch of other options you can do with your account.

If you still don't know where is that, here's the link.
http://forum.toribash.com/tori.php

Thank you

Question answered, closing thread.