Can I exchange Bitcoins to get Dollars? If I get some Bitcoins, Is it possible to sell it and get Dollars?
Yes, Bitcoins are exchanged for a variety of different currencies and goods, definitely including US Dollar, Canadian Dollar, New Zealand Dollar, probably also Hong Kong Dollar, Namibian Dollar, Singaporean Dollar, Taiwanese Dollar, maybe even Brunei Dollar, Belize Dollar, and Namibia Dollar.
In general it is expected behavior for currencies to be exchanged for one-another. There exists at least one exchange course for each currency pair. Here is one example for Bitcoin and US Dollar: CoinDesk Bitcoin Price Index
As to where and how you can exchange Bitcoin for Dollar and vice versa, you can find many questions here discussing that. See for example How do you obtain Bitcoin?, What's the best place to sell bitcoin in Australia?, What are the options available to convert Bitcoin ot Paypal-USD?. You can find a better fit by using the search function with the appropriate input terms, e.g.
sell bitcoin usd.