No one can tell you if you're too late. They've been around a while so you're not going to get the benefits of day 1 adoption. However, it's also not mainstream yet. I pay more attention to Ether/Ethereum and I am bullish on it long term due to the Ethereum alliance which is an organization of businesses that are pooling resources to build applications for Ethereum. On the one hand, the hype headlines seem to be positively influencing prices (they recently announced new members). However, investing based on hype is obviously not a very fundamentally sound method.
My advice is to read for a few hours so that you understand the state of the ecosystem and what each coin is about. The most accessible coins are bitcoin, ether, and litecoin probably in that order. I am a believer that what is good for the goose is good for the gander so I support all crypto. Certain parties believe that the success of cryptos other than "theirs" is detrimental to their interests so there is definitely some bias in articles and reporting sometimes.
The simplest way to get in is to open an account on Coinbase or Gemini and then buy whatever coins you choose. You can buy any amount you want, so I can't advise a dollar amount, just be aware of the fees involved. All investments have risk, I'm not a financial advisor, YMMV, don't listen to a stranger on the internet, etc.
