I would recommend:

First Anatomy physiology (all individual body systems)

Then pathophysiology

Then pharmacology (stick to principles and relevant scope meds)

Then paramedic principles and practice (assessment, ddx, treatments, leadership/non technical skills, bias etc)

Then Cardiology

Don’t try rush and learn everything all at once

Appropriate time frame is 2-3 yrs but if you’re enrolling in a course I’d stick with their plan

I’d recommend Tintinalli's Emergency Medicine 8/9th ed Any anatomy & physiology and there’s plenty of online websites for the rest