/fa/ - Fashion

Sorry, didn't know whether to post this in /trv/, /adv/, or /fa/, but I figured start here first.

I'm visiting distant family for 3 weeks in Serbia and I want to make a good impression, but all I own are old clothing from when I was a fat beachbum slob. It's gonna be as cold as shit over there, I'm gonna be there for 3 weeks, and pretty much everything I own is a short sleeve t-shirt with cargo shorts and sandals. I have absolutely no fashion sense; add on top of that that I've never been on a trip this long, in Serbia, or even seen much could weather before and I'm like 400% lost.

Would anyone be able to detail some kinda shopping list to follow for a 3 week trip to the Serbian cities and towns? How many pairs of pants/shirts/shoes, what types for which situations, coats/jackets needed, etc, and where possibly I can get it all for a decently low price? Whatever I can't buy with what little money I have I'm probably going to borrow from my dad's big-ass closet.