I have a Hero 3+, I just gave it to my daughter. It does still take good video. The audio will be pretty bad especially if you have to put it in the waterproof case. The newer cameras don't require a case to be water proof and now have 3 external mics. The stabilization on the newer cameras is really good as well. So in my opinion it would be worth using but for B roll shots. The newer cameras are better but can be pricy. But you cant beat free !!

Which version of the 3 were you given, Black or Silver?

If you have a modern smartphone, the GoPro isn't really worth using other than for action shots that you can't use the smartphone. For example, mounting the GoPro onto the front of the canoe to film you while paddling. And even for those shots, the quality will be sufficient, but not amazing. Anything handheld your smartphone would outperform the GoPro in pretty much every way.

Newer versions of GoPro's have amazing stabilization, really good specs for resolution and slow-mo, much stronger image quality processing, default waterproofness without housings, voice commands, better microphones, and a ton of other stuff / useful features, like setting a recording timer so you don't need to wake up to start filming a timelapse of the sunrise (for example).

If you were given it for free then of course it doesn't hurt to give it some use for personal fun, but if you were wanting to start creating content with hopes of gaining traction on social platforms, for example, then I wouldn't recommend using it.

I'm no GoPro expert, but if this model has a time lapse feature you can sure have some fun with that.  That's one of the most enjoyable features I use on mine.  I use time lapse for all kinds of junk just to see.