I like and use Benjamin Moore colors. They have many gray shades to choose from. I would do walls in the gray and keep all trim white. You can mix up the grays,so. In darker rooms use a lighter shade, etc. always buy sample colors and put on walls to see in your light .

I know it's very very hard to choose a gray. Gray has different undertones--blue undertone, brown undertone, or purple undertone. From what I read, first you need to decide which undertone you would prefer, and then go from there. On Benjamin Moore site, you can find their most popular grays and go from there. As to a white, Dove White is one of the most popular on Houzz to go with gray. There's an article on choosing the right gray too, on Houzz. Just search "choosing the right gray".

Here's the link https://www.houzz.com/magazine/choosing-paint-how-to-pick-the-right-gray-stsetivw-vs~454963