Hi, I hold a few tokens of varied nature and a few coins. I have setup a few eth addresses for the younger members of my family. I am talking about kids that are less than 3 yr old 
So, what would you include in their new accounts, so that they can use it in 15 yrs?
You should visit the coinmarketcap site. Can you find a list of currencies to invest in. You should choose the top 10 in the market. These currencies tend to be more stable and longer term.BTC, ETH, XRP, BCH ... are examples for you. So, what would you include in their new accounts, so that they can use it in 15 yrs?