At home you can use any of the cheapo pans you can get on places like Amazon, and they're all prefectly fine. Most of them are non-stick, and that makes things infinitely easier, especially because they are all pretty small. The copper ones usually turn black...I don't think the tin or whatever they use to clad the inside is supposed to stay shiny like a French copper pan. If the work pan you have is one of the big square ones, practicing on a small one at home will not be much of a help. It is MUCH more difficult to make tamago with a big pan, and the copper ones stick much more, especially with sushi tamago because it has so much sugar in it. There is no way of getting around a huge number of F-ups when you learn. My advice is to borrow the work pan after service, or use it when nobody's around, and do nothing but make tamago for like five or six hours. Buy three hundred eggs and just go for it. They will be piled on the floor after the first hour, but eventually you'll get the hang of it. Even if you do buy a copper one, they don't really work well until they've been seasoned with a lot of use, which will make your practice much harder.