As others have mentioned there are various exchanges that will allow you to withdraw your bitcoin to fiat, you will need to abide by their KYC - know your customer process which means confirming your identify which might take some time.
You could also use a debit card which you can find loads of information about by searching the forum, with any option you choose there will be fees involved in the conversion.
You can anytime convert it into cash. Bitcoin is an easygoing currency and its easily convert into in cash. Bitcoin is just like cash that any time u sale your Bitcoin and convert it into cash. Trading on Bitcoin is a great fun. Your Bitcoin is like cash in your hands. Whenever you need for money you just sell you Bitcoin in good price and get cash at once. Bitcoins price is growing up daily. So it is better than cash.