What is your background/perspective? For introductory motivation, check out https://www.shapeoperator.com/2016/12/12/sunset-geometry/

And perhaps follow up with the GA for Computer Science book, or if you like (or want to learn about) Newtonian mechanics, try Hestenes’s book New Foundations for Classical Mechanics.

For people with a mathier background, I would recommend https://arxiv.org/abs/1205.5935

thank you, this looks interesting. The parent comment caught my eye since I'm pretty comfortable visualizing linear algebra with 2D arrays but struggle beyond that.

Edit: Better link: https://www.av8n.com/physics/clifford-intro.htm

https://www.av8n.com/physics/spacetime-welcome.htm

Geometric Algebra For Computer Science, An Object Oriented Approach to Geometry, published by Morgan Kaufmann Publishers http://geometricalgebra.net

David Hestenes: New Foundations for Classical Mechanics https://www.amazon.com/Foundations-Classical-Mechanics-Funda...

Geometric Algebra on euclideanspace.com by Martin John Baker: http://www.euclideanspace.com/maths/algebra/clifford/index.h...

Linear and geometric algebra

Vector and geometric calculus

Both by Alan macdonald, both very good.