Given that Unity is primarily a game engine, I've found that learning how to build basic games is one good way to get used to the overall workflow. I mostly refer to YouTube videos + the Unity forums, so most links below are of video tutorials.
This is basically a rite of passage. Not the most interesting of starts, but covers the interface and basics to a decent extent.
The Unity Learn website has a bunch of nice tutorials for focused projects, like making games similar to Flappy Bird or Plants vs Zombies.
Probably one of the nicest Unity YouTubers out there. Goes over the basics really well in this video series.
All of his Coding Adventures installments are fun to watch and learn from, I first found out about him from this series on Procedural Terrain generation.
Also probably one of the nicest Unity YouTubers out there. Has tutorials on pretty much every major feature of Unity or issue you might face.
A more detailed starting point, that assumes a decent background in coding and math, but is a good resource regardless. Focuses a lot more on physics and graphics applications within Unity.