L3-edge RIXS can probe orbital, charge and spin excitations and the possibility to measure the polarization of scattered photons can greatly help the assignment of spectral features. Here, we present a study of orbital and magnetic excitations in cuprates, made at the ID32 beamline of the ESRF with full polarization selectivity and 70 meV instrumental band width. The device installed on the high resolution ERIXS spectrometer is based on a polarization-selective optical element and allows the measurement of the degrees of linear polarization of the scattered radiation. We measured Cu L3 RIXS spectra of undoped, underdoped and optimally doped NBCO at two different in-plane momentum transfer (q//=0.2 r.l.u. and q//=0.4 r.l.u. in the 10 direction) with both σ and π incident polarization. These measurements, with the support of single ion model calculations, allow us to better determine the polarization dependence and the evolution of dd excitations at changing doping and scattering geometry. Moreover, we can disentangle different contributions due to the spin and charge in the low energy scale and in the mid-IR energy range of the spectra.