There is no need to change your name when you become a Buddhist. Most people do not. Even monks and nuns didn’t change their names when the Buddha was alive.
If you would like to have a traditional Buddhist name, you certainly can. Some names are are simply names of famous disciples such as Visakha (chief female benefactor), Khema (chief nun), Ananda (the Buddha’s attendant), and Upali (Vinaya master). Some names are wholesome qualities such as Khanti (patience), and Samadhi (concentration).
If you would like help choosing a Buddhist name, most monks and nuns would be happy to help you.