I'd wear some kind of work pants or hiking pants with side pockets and durable material. Even without encountering zombies, I'd need to carry essential tools and enough of a base kit to survive for a day or two if something prevented me from coming back the same day. A backpack would be good to have but ideally it should be for loot and discardable if necessary. So pockets are ideal.
I'd have thin gloves, like the ones mechanics use. This is for being able to move stuff around without being worried of splinters and other kinds of wear on the hands.
Shoes would also have to be working/safety shoes with a hard toecap, not just for safety, but similar to the other stuff it's about not having to worry about it when moving and ravaging through things.
For tools I'd like to carry a screwdriver with exchangeable bits, pliers with a cutting edge, a knife and pen/paper.
A hoodie with a zipper for warmth and flexibility.
It's realistic, because that's basically how I dress up to do DIY around the garden and house. I normally wear much lighter clothes, but for working with DiY I prefer wearing this "suit". It might be slightly heavy but it's liberating not having to worry about touching anything with any part of the body.