These vectors randomly get inserted inside the host cell genome, although with preference for actively expressing loci.
The portion that gets inserted is enclosed between the RRE element and the 3' LTR, orange coloured zones.
Once lentivector is integrated inside the host cell, I use Puromycin to select the positive cells, the selection is fast and clean. You can check it by analyzing the GFP expression by microscope or preferably by flow cytometry.