There are several (and a growing number) of ways to sell your bitcoin and/or convert it to cash.

While many people treat bitcoin as an investment tool rather than a currency, it arguably remains more liquid than some investments with similar volatility. Exiting your position in bitcoin when you desire, at least for now, can be a convenient and fairly easy process.

Many exchanges exist online that can help you convert bitcoin into any currency you would like.  These function much like other currency exchanges in the world, but you should be careful to use one you believe is trustworthy.  Researching the topic on social platforms that demonstrate trust through upvoting, such as Reddit, may help you learn more about what other people believe to be good ideas. The landscape is frequently changing, so finding up-to-date information is key.  

You could also exchange your bitcoin for goods or services that have value to you. In 2016, Visa began offering bitcoin debit cards, which allow users to deposit bitcoin balances onto the card, where they are immediately converted into one of the supported currencies in your region, and the money is immediately available for use anywhere that Visa debit cards are accepted.  The debit cards can even be used to extract cash from ATM machines.

One other convenient but similar way to swap bitcoin for cash is to convert them into dollar-amount gift card balances at major retailers such as Amazon, which is currently accepting bitcoin for gift card purchases but not direct merchant purchases. You may also be able to find a buyer on a peer-to-peer marketing website like localbitcoins.com, where users can look for buyers and sellers close to their geographic location, and choose what kinds of payment methods they would be willing to accept.