1. Best exchange to join
2. Best altcoin to invest in
If you want to engage in cryptocurrency, then you can invest not only in bitcoin, but also in other coins. There are many interesting alternative cryptocurrencies. I like Etherium, Ripple, TRON, USDT. The best exchange is of course Binance.
USDT? USDT is not the best cryptocurrency, are you investing there? It would be a waste of time in my opinion,
for your choices on Ethereum, Ripple and Tron are good, because these three coins have the potential for huge increases.