This would be my essentials list. Mind you that I'm listing down the basics I believe should be your foundations when building a better wardrobe going from casual to formal. I feel that a lot of these can be mixed and matched and can build plenty of outfits. The white sneakers should be as simple as jack purcells, stan smith's, etc. along those lines. For grey sneakers I would choose a runner style. Of course the fit and quality of the item should be the most important factors. Feel free to add on to anything else I missed, I excluded socks and underwear because those are automatics as essentials.
white v-neck undershirts
white dress shirt
white or blue oxford cloth button down
blue gingham shirt
blue chambray shirt
tan chino pants
navy chino pants
dark denim jeans
navy suit
charcoal grey suit
navy tie
navy knit tie
dark red tie
navy blazer
navy or charcoal peacoat
denim jacket
grey hoody
black dress shoes
brown dress shoes
brown desert boots
white sneakers
grey sneakers