First shoot tomorrow need tip

I will be doing my first ever shoot with a model tomorrow.
I have one AB800 with a whit/silver umbrella.

I don't want to spend much time figuring set up when she gets here so:

Backgound: Semaless White or Neutral Gray ( I think i may do gray)
If I want the least harsh lighting would I use the White bounce & not silver?
I heard that the closer the light source to the subject the softer the light on the face?

I will be using my EF-s 60mm f/2.8 and the 70-200 f/4L

I plan on placing the light on the left of camera.

I will have all the windows blocked so it's controlled lighting even though the light from windows is difused with translucent paper right now.

Thanks in advance

I want to only bite off part of this:

The closer the light is to the subject the softer the light (be it face, fender, or frog). But, moving closer than the diameter of the light source will not garner any additional softness. So, if you have about a 40 inch diameter umbrella, distances closer than 40 inches will basically be about the same as at 40 inches.

I would suggest that if you only have one light, that you fashion an ad hoc reflector of some sort to be used as a fill. You can use a piece of foam core, a piece of poster board, a piece of cardboard covered with crinkled aluminum foil, etc.

This reflector will act just as another light, but it will be impossible to get the reflector to be any more than about 1/3 or 1/4 the intensity of the main light (possibly less). But, it will fill in dense shadows just like a fill light.

Test whatever setup you decide on in advance. If this is the first time you are doing this, do not walk in cold. Have a dress rehearsal using the exact setup you plan for the session.

Unless you are in a huge area the 70-200 is likely too long. The 60 might be fine, but so would your kit lens. No need for perfect optical properties for pleasing images of human beings. Mostly they like things softened a bit anyway. So, the 18-50 near the long end might be about perfect.

Enjoy! Lon

Thanks londuck. The info helps me a lot & the umbrella is a 48' diameter.