Crypto's. Besides coinbase which Im currently
Using however I'm looking to expand outside of
What coinbase offers
You need to go on to the particular site to get access to their platform, by registering and depositing the money.
I would suggest you using poloniex, it has the highest volume among the other exchanges, plus they give you a chance to trade also altcoins- only those trusted ones, not scamcoins.
The only disadvantage I have found in Poloniex exchange, is that their platform is a bit laggy sometimes, which may be really annoying for experienced trader- we need to make our decisions in a blink of an eye.