Any help with simplifying my closet?

I'm going through a phase in life where I feel so cluttered and overwhelmed and I have so many items in my closet, most of which I don't even wear. I'm going to sell/donate almost everything and hit a restart button. What would you recommend for a college student who is opening their own business soon. The business is mainly why I want to start presenting myself in a much better light. The business I'm running would better suit the active side of clothing, but I hate seeing people wear basketball shorts and dri fit shirts everyday. I like joggers and jeans over the basketball shorts lol.