I think i may have a virus but dont have a anti virus because i find them annoying and dont usually click on weird shit anyway. is there a legit website that will check my computer for a virus? or a program i can use?

my buddy used my computer and now whenever i go to imgur, the colors are shifted and sometimes reddit loads in codes and youtube videos play but there is no motion just a still frame and sound and if i close chrome and re open it the video plays fine. i am using a HP desktop on windows 7