Yeah seconding this. If your work is putting you somewhere you need protective equipment they should provide it or a budget for you to get your own. That’s how it works in the UK at least, it might be worth asking if they provide a budget or anything.

Otherwise for boots your first step is to get some decent socks, I’d recommend wool outer layer and something absorbent as a base layer. Then you want to go try on some leather boots with a rubber sole wearing your socks, you might want to get a slightly bigger size so you can put an insole insert in as well. Make sure the boots aren’t too tight with your extra socks on as you need space to trap the heat but they shouldn’t slide around.