No, physics is very easy and anyone can learn it (at least at the undergraduate level; it will often take you a week to solve a homework problem, but that's the same for 99.9% of physics majors) - as long as you are interested in it and curious about the questions it asks, and you have teachers who love the subject and care about their students (the teachers are not so important, but it helps). Anyway, most football players solve in practice problems that would be much too hard to put on exams. So this should not be an obstacle.
As for going from physics to engineering, I have no idea. One possibly useful resource is "Landing Your First Job: A Guide for Physics Students" by John Rigden. It's published by the American Institute of Physics, and the physics department or career office at your school might have a copy.