I started to pay attention to Bitcoin and Altcoins about 2 years ago. Since then a lot of changes have occured. I have also learned a lot about them. That they are the future, or at least will make a big impact on it. Also that there is plenty of money to be made with them. They fascinate me and yes the money is a big plus.
There are many ways to get your USD money into it, and I'm going to tell you how I have done it without any problems to date on getting scammed. I purchase my coins through www.coinbase.com. There you can select Bitcoin (BTC), Ethereum (ETH), or Litecoin (LTC). I always choose litecoin because the worth of a litecoin is similar to the worth on many of the exchanges. While BTC and ETH have bigger gaps in their worth.
I then transfer my coins to my Poloniex or Coinomi litecoin wallets, and from there I can exchange for many other altcoins.
I will add more to this post later, above is just to get started.