Conservative vs Dissipative Forces

I will be speaking very loosely since I am not a physicist.

Say a system evolves via a dissipative force, then usually as time moves on some energy functional will be decreasing.

If a system has both dissipative forces and conservative forces then isn’t the "net force" still dissipative its like saying $-$something$+0=-$something? Hence wont this dissipative conservative system also minimise some energy functional?