Perhaps the easiest option is to use an online keyboard. I recommend the Int IPA keyboard.
Simply click on the symbol you want to type, and it will appear in the box at the top of the page. Just copy and paste into your document.
Another way to type IPA symbols is by using a keyboard layout. These map the keys on your keyboard to a different set of symbols, usually through the use of key combinations or key sequences. This is more convenient than an online keyboard if you're going to be doing a lot of typing, but there is a bit of learning curve, so it may not be worth your time if you are only taking an intro linguistics course.
SIL IPA keyboard for Keyman (Windows, Mac, Linux, iOS, Android, and web)
IPA Unicode keyboards from SIL (no longer maintained)
SIL used to maintain a number of Unicode IPA keyboards for Mac, Linux, and Windows. They no longer maintain them, but most of them still work if you'd like to give them a try.
IPA Palette for Mac (((discontinued but may still work)))
I really like(d) the IPA Palette app for Mac. It provide(s/d) an IPA chart interface to insert characters into any Mac app. The app still works, but the developer is no longer updating it—this means it will probably stop working at some point.