I believe it's classical physics, you are interested in.
MY humble suggestion is this
To start (get this is you can afford only one book):
French - "Newtonian Mechanics"
(it's not only about mech, it's about physics and how to study it)
To move on:
Kleppener Kolenkov, "Introduction to Mechanics"
French, "Vibrations and Waves"
Kip, "Fundamentals of Electricity and Magnetism"
Purcell, "Electricity and Magnetism"
Callen, "Thermodynamics and an Introduction to Thermostatistics"
Basic statistics for error analysis
Taylor, "An Introduction to Error Analysis: The Study of Uncertainties in Physical Measurements"
*insightful* --> Feynman, "The Feynman Lectures on Physics" (they are online for free!!!)
*quick reference* --> Ohanian, "Physics" 2 edition expanded (newer editions look worse in my eyes)
Oops, I see now you posted "want a book about relativity?" (it would be nice if OPs had some sort of colored background to make it clear when they re-enter the thread... I tend to overlook the names...)
Taylor, Wheeler, "Spacetime Physics" (to begin with)
I have not found one single textbook that satisfies me, but let's say that
French, "Special Relativity", albeit a bit old and still using relativistic mass to some extent is a nice entry point for a beginner