At the side there's a lot of suggested groups that I find annoying and offensive, for example ones involving religion. Is there anyway I can hide them? Can I use Ad block plus to hide them?
There is a browser extension called Social Fixer that can, among many other things, permanently hide parts of Facebook pages.
You can get it at http://socialfixer.com for Firefox, Chrome, Opera, and Safari.
After it's installed, hover over the Suggested Groups section, and an X should appear. Clicking the X will hide the area permanently (or until you change your settings to get it back again).