It will be never a mistake if a newbie decides to invest in top-10 cryptocurrencies. However, here I will not recommend him to deal with Ripple, as too many coins have been circulating on the market. XRP price can drop.
Ripple is also completely different from all those other coins that are in the top 10 right now.
The supply ins't an issue actually, XRP did fall but it's because of the bear run, but looking its achievement in the bull market, it's the most profitable coin that time.