Every time I see the caustic truck delivering to the alcohol plant I hang around I get a wee bit nervous. Any time they gotta dress up a trucker like a fireman means some bad stuff may happen. My pea brain tells me avoid avoid avoid!
Back to the OP question get some steel toed boots and couple of pairs of good walking shoes/boots. Unless a shipper requires steel toed boots I usually wear ankle high walking boots. The extra pair is for when the boots I'm wearing get wet.
Most national companies have one major requirement regardless the shoe. MUST BE SAFETY TREAD! What you desire beyond that is up to you. Steel toed probably will be required if your running with skateboards. However if you are with a van national carrier most of your loads will be touchless. The only places that I have seen that you needed knee boots were usually in truck stops. So ask your company what they require, not what the board suggests. As far as the hard hats, this may be supplied by the company as well (again check with the company).
I have 3 pair of Cabela's Merrel knock off's that I wear all the time, great traction, waterproof, I paid $25. ea for them, that is all I wear to work. I carry a pair of boots in the truck incase I need them, but my knock off's I wear even in deep snow while chaining up.
I wear some comfortable sneakers for driving. I brought along a pair of workboots but never used them.