Abbott's intro to analysis. U can literally just start with no knowledge. Every chapter starts with motivation into problems and theory. In addition, everything is fully contained, so no need to refer to outside sources, except maybe as a help to writing some proofs for exercises.

This is literally my favorite textbook. I hated calc and diff eq textbooks because while they are intuitive and motivation is the topic itself, you are kind of just doing operations without understanding the meaning. Once I hit college math and read this gem, I was blown away.

Another great textbook is the chartrand introductory graph theory. Provides great examples, diagrams, and practice problems that are not only theoretical, but also applied. Graph theory is fun.