So I bought a GFCI outlet to changeout a regular outlet and when I pulled the regular, it had white wires/neutrals on both left side screw connections and one black on the top right connection. I do not know what I should do for the GFCI outlet as the top two connections are line and bottom two are load, so I cannot hook up three wires (not even sure why a regular outlet would have two neutrals and one hot). Any thoughts would be appreciated. Also next to the outlet is an existing switch in the same larger outlet box. I do not know if that would have anything to do with it, not sure why, but that is the situation.
The first rule of GFCIs is, if you don't really know how LOAD works, don't use it.
On a plain receptacle, the extra screws are spare terminals (unless the tab(s) are broken, then different deal). Not on a GFCI.
This sounds like a picture postcard case of "don't use LOAD". (I know exactly what it does and I wouldn't use it either). Either pigtail the 2 wires to the 1
LINE screw, or most GFCIs provide a method for back-wiring 2 wires onto 1 screw, in which you insert the back-wire and tighten the screw (a lot) to clamp them.