I recommend BTC, ETH are the best currencies for invest money because we can analyze with the previous data of the charts and we can get more idea about the up-trending both of currencies. But if you have significant knowledge about altcoins then you can invest in altcoins also. but peoples want to more carefully before investing in altcoin because if you don't know about the future of the market which related to the crypto that you are willing to invest in, you will lose your money completely. Solona is the nearest example of an altcoin. if you enter the right position at the right time then you will be rich.