I suggest investing into the top 10 as these coins have stood the test of time.
Always remember, investing does come with a risk therefore never risk more than you can afford to loose. Also, think about what you mean when you say you want to invest. Do you want to day trade? Do you want to invest in the companies? Or, do you want to buy currency with the hope it will appreciate in value?
Before placing your hard-earned money into the cryptocurrency space I suggest you learn about the coin fundamentals using the recommended reading. Start spending your time and energy learning, discussing, using, coding, and enquiring about the coins.
These in-depth guides will be helpful for your research:
www.cointelligence.com/content/ultimate-bitcoin-guidewww.cointelligence.com/content/ultimate-ethereum-guidewww.cointelligence.com/content/ultimate-litecoin-guide