You can invest in equipment to mine Bitcoin, but if you hold the Bitcoin that you mine, then you are speculating.
To answer (or dodge) your original question: nobody knows for sure if its too late.
As of right now, the market is betting that it is better to own a Bitcoin than to hold $5,663 in cash. (The current price is $5,664.)
Coinbase is your best bet for getting started in the US.