Many unicode characters show up as little squares
I've been doing a fair bit of research on various scripts, and am realizing that many alphabets and abugidas aren't recognized on my computer (mid 2015 MBP, Sierra 10.12.6), instead showing up as blanks squares. This includes some fairly widely-used scripts such as Burmese or Tifinagh (screenshot attached). These don't show up on any browser, nor when pasted into Word. Is there a way around this very frustrating issue?
MacBook Pro 15″, OS X 10.10