Bitcoin is digital money that you can send anywhere in the world without banks. It was launched in 2008 and is currently approaching 110k. It is fast, secure, and limited: only 21 million will ever exist. Ideal for learning to invest with little money.
Advice:
Don't try to understand everything at once. Start with the basics: what Bitcoin is, how to buy it, and how to store it. Learning about cryptocurrencies is like learning a new language: step by step, and with daily practice.