lose fat and build muscle?

You can't really choose where you will lose fat from, but a lifting routine will help you to lose fat and build muscle, giving you the look your are seeking. Some popular lifting routines that many women here use are:

Stronglifts
Strong Curves
New Rules of Lifting for Women

I'm sure there are more, put those are popular to start with.

Do your cardio to lose fat, your body will choose where it takes your fat from first and last. Experiment with different forms of cardio and timing to see what your body likes best. Then do bicep curls, tricep presses, etc. for your arms, do your shoulder presses and lateral raises, too. For your legs do squats, deadlifts, barbell hip thrust, cable kickbacks, etc.