The easiest way to learn to use SnapPy is to watch the screencasts available on YouTube:
Intro and quickstart: an 11 minute video with the basics: Part I and Part II.
An hour-long demo Practical computation with hyperbolic 3-manifolds, recorded at the Thurston Memorial Conference.
The SnapPy 2.0 new feature demo.
SnapPy, SageMath, and Docker are friends with associated materials (4 pages), including homework.
Notes, problem sheets, and references from the LMS-CMI Research School in Warwick in 2017.
Another hour-long demo Practical computations with hyperbolic 3-manifolds given at ICERM in 2019.
The key thing to remember when using the SnapPy command shell window is that you can explore objects using introspection and tab-completion:
In : Manifold? <hit return-key> ...instructions for creating a manifold...
So now we create a manifold:
In : M = Manifold("m004")
But what can we do with it?
In : M.<hit tab-key> ...list of methods...
What does the “cover” method do?
In : M.cover? <hit return-key> ...description of cover method..