Not long ago, I posted in frustration at a lack of training a friend had. Honestly, there's not much anyone can do, though. My friend was hired a month or two before the seasonal hires, and now, he's having to help them learn. Pretty crazy considering that he was frustrated and worried about his own lack of training not long before they came along. Suddenly, that fear went away. Why? He suddenly realized how little they knew in comparison and realized how much he really did know at that point. It just took two months or so to get there even if he still has issues.
The truth is that no one can tell you how to do the job outside of the basics. It takes time, and trust me, it takes much longer than you think it should. Why? To accomplish everything "expected" of you, you have to know the store, the aisles, the general locations for things, and all of the protocols and procedures that come from just working day to day. Anything you don't know, ask even if you've already asked. If you're asking how to backstock something for the 30th time, you might get some annoyed looks, but if you're wondering where to place backstock for a certain item that you're unsure of to make sure you're not pissing off your pals in the backroom, ask them. My friend is still asking questions or making sure things are supposed to be done a certain way in rare cases, but he's been told that his desire to learn and get it right is a major positive.
MyDevices help a whole lot, and for anyone relatively new, they're a must. After a few months, though, not having one just means that you'll have to call the back to check whether an item is in stock more. It's intimidating at first to see people spouting off the exact location of items, but soon, you'll realize they learned that after looking a million times.
As for the walkies, communicate. Always communicate. Hear a hardlines call come along, but you're across the store? A simple "Hey, I'm on the other side of the store. Can someone else grab that?" is all it takes... and then if no one responds with 15 seconds left, get to sprinting! Seriously, though, don't stress. Every person has made the same mistakes, struggled with the same things, and had the same emotions. Just go out there, try to be an asset to the people you're working with, and you'll be fine.