Female, and I've done 4+ years working in a warehouse for a charity: a lot of walking and moving boxes, sacks and roll containers (the tall cages). Best tip is to wear work socks (so thicker than normal) and get a good pair of insoles for your footwear, something like Scholl GelActiv work ones. I assume you're in safety boots, so make sure they fit well; sometimes the trainer-style ones can be better than higher boots as they don't put pressure on your Achilles.
Make sure you have had Manual Handling training from the company and that this has been recorded. If there is anything that goes against health and safety or that would make things easier you should flag it up.
I also walk to and from work (about 35 mins each way) which has helped me be used to being on my feet, and I wear good quality trainers, again with decent insoles, so look at what you wear outside of work as you might need more support for a while. I don't do any other exercise outside of work, though I am thinking of starting dance aerobics again for fun.
Make sure you sit properly and don't slump especially if tired, and are comfortable in bed.
You do get used to it! Took me about 3 months. I'm now fit enough that I also go out with our male drivers and help move furniture that is being donated or delivered, including wardrobes and sofas!
If your pains do continue after trying these, do see your doctor.