I want to take several courses of MIT OCW, and I'm searching for study groups. Is this website the place to find them?

No, this website is not for study groups. It's more of a 'question and answer' website. There is no actual communication on one certain subject. Although I do know a few websites that have worked really well for me, where you can create and participate in study groups;

-studyblue

- studyhall

- getstudyroom

all of these are safe websites that are used by wide variety of students, therefore i'm sure you can find plenty of people interested in learning the same things as you!