I recently purchased a website and I am very new to webdesign and using Pretashop (Insert any ecommerce site) I started exploring the site and found themes online and added them. I noticed that once I changed the theme, some part of the old them would still be on there and no the site, is full of different themes and looks horrible. How can I fix this? How this this happen? and How can I prevent this from happening again, PLEASE HELP!!! ATTACHED IS A PHOTO OF MY SITE NOW