How do i add an N-Ch Mosfet IRF540 to the components listed in Fritzing? There is a P-Ch Mosfet in the inspector Listt

The magnifying glass icon in the parts bin on the right hand side of the Fritzing window. You need to search for mosfet (as there isn't a irf540 directly) and that will turn up a bunch of choices in various cases. You likely want the Basic Fet N-Channel which is a TO220 footprint (which should be correct for an IRF540 I think unless yours is surface mount).