I have been trying to learn some things in PDE at an undergraduate level. I have been studying from Strauss' Partial Differential Equations: An Introduction, 2nd Edition.
I particularly am interested in learning how to take Fourier transforms to solve ODEs and PDEs like those of simple heat transfer equations such as $ku_{xxx}=u_t$ with whatever initial/boundary conditions provided. Strauss' text has been confusing me a lot since it feels rather unorganized and teaches how to solve some of these PDEs using very specific examples. I am wondering if anyone can point me toward a more general undergraduate level text on PDEs that covers Fourier transforms/series both concisely as well as in a structured way? Thanks.
Note: Particularly, I have taken/studied related undergraduate courses including ODE, Multivariable Calculus, Real Analysis, BUT NOT Complex Variables.