Can You Help My Set Up A 3-Column Masonry Layout For All My Blog Category Pages?

Hi There,
First of all I need to reinstall Highend because I was first told by a support team member that I could not organize category pages in masonry format, so I bought & installed another theme. Then, on the public forum, an administrator told me that I CAN set Highend up the way I want. I’m going to to try to do it myself because I’ve sadly spent so much money at this point. Then, I would be so grateful for some help setting all my category/archive pages to a 3-column masonry layout. Thank you for your time and patience.
Sincerely,
Morgan Marie