Unfortunately, all you can do is leave them on the floor. Yes, really, just leave them on the floor in your house until you want to sell. There are no consequences to leaving your turnips on the floor. If you really want to get into the stalk market, consider making one of your rooms a dedicated turnip cellar.
All you need is the master log in, and you can turn on chat somewhere. I did it when I was 12 and I had my legit brithdate on. You can message KingsIsle support at [email protected] . There’s no guarantee that they will change it for you however.