Court outfit

I have court tomorrow morning and I'm not sure what to wear. My friend was supposed to let me borrow her suit but then bailed on me today. I have black slacks and closed toed flats that I can wear but I don't feel like I have an appropriate shirt and I'm very broke right now. Would just a plain long sleeved shirt work? Or is that too casual?

Also what should I do to my hair. It's about an inch passed my shoulders. I usually just straighten it, but should I wear it up or something?

I'm going up against my ex for aggravated assault (he's being charged) and I know he will be in a nice suit so I'm worried I won't look nice and I know how much appearances mean.