The easiest way to get cryptocurrency is to buy it on an online exchange like Coinbase.
On Coinbase, you can buy major cryptocurrencies like Bitcoin (BTC), Litecoin (LTC), Ethereum (ETH), Bitcoin Cash (BCH), Ethereum Classic (ETC). Or, explore emerging coins like Stellar Lumens or EOS. (For some cryptocurrencies, Coinbase offers the opportunity to earn free money.)
A good approach is to ask yourself what you hope to do with your cryptocurrency, then choose a currency to help you achieve your goals. For example, if you want to buy a laptop with cryptocurrency, Bitcoin might be a good choice because it is the most widely accepted cryptocurrency. On the other hand, if you want to play digital card games, Ethereum is a popular choice.
Remember, you don't need to buy a whole coin. On Coinbase, you can buy parts of coins in increments as low as $2, euros, pounds, or your local currency.