I started learning Unity back in version 2 when it was Mac only. They used to deliver with each version a well done good demo project proving the engine capabilities and not requiring a high end development environment to play them. Now days the demos are available from the Asset Store but there were a couple of them that helped me a lot.
So, to not boring you with my poor English grammar I have:
Island Demo (Unity 4)
Bootcamp Demo (Unity 4) and can be ported to Unity 5 prior Unity 5.6 with minimum changes
Just PM me I'm willing share them with you since they provided a good learning reference