If a car is traveling at a constant rate, is it accelerating?

This really depends on how your asking the question.
So a constant speed for example is 10 miles per hour. 10mph

Its constantly going at that speed, it already accelerated so it’s not accelerated but more so as a sturdy rate.

Yes, anytime the velocity is constant, the acceleration is zero. For example, a car travelling at a constant 90 km/h in a straight line has a nonzero velocity and zero acceleration.

it is an infinitive phrase with a subject.

he licked four girls