How to report a bug (16.04 freezing, peristently)

my Ubuntu 16.04.2 (on my yoga 2 11) installation keeps freezing, causing me to have to force reboot. This is a persistent issue, and is not caused by any proprietary kernel software being in use. I'm not sure how to look at the logs to see what is causing it, or how to report the bug if it's a bug I'm experiencing, but some guidance would be greatly appreciated. If it helps, I always have my laptop plugged into my tv? (which is how i know the system is freezing copletely- the panel clock stops counting the seconds when it freezes)