One of the early hurdles in physics can be understanding that measurements often come in two parts including magnitude and direction. Velocity, acceleration, force and work are all examples. In physics, a negative value is not less than one that is positive. This downloadable PDF specifically addresses these ideas in the context of the differences between vectors and scalars, their applications, and how to use them in equations. You should always give things a try on your own first, but if physics isn't clicking you should get a science tutor in place.