Have a look for resources on the finite-difference time-domain (FDTD) method for electromagnetic simulation. Also in use are the finite element method (FEM) or the method of moments (MOM). Wikipedia has a decent-ish rundown https://en.wikipedia.org/wiki/Computational_electromagnetics.
The Art of Electronics will not help you for simulation, it's a very good practical manual for analogue electronics design. It'll help you understand how a circuit works, but electrical engineers rarely need to solve Maxwell's equations when designing a circuit. It's not a bad idea to read through it however, I can't see many situations where you'd immediately dive into EM simulation without understanding how the circuit works first.
The Art of Electronics will not help you for simulation, it's a very good practical manual for analogue electronics design. It'll help you understand how a circuit works, but electrical engineers rarely need to solve Maxwell's equations when designing a circuit. It's not a bad idea to read through it however, I can't see many situations where you'd immediately dive into EM simulation without understanding how the circuit works first.