Dubrovnik is a tiny, compact walled city...you won't have any issues with your hotel because they have a very good bus system in case it's a bit far to walk. Have you looked up your hotel location on Google? It's very easy to get walking distance and directions straight from Google Maps. I rented an apartment inside the City Walls but cannot remember the name (it was several years ago). It was nice to be right in the center, but not necessary. There are a lot of hotels in the Lapad neighborhood outside the city walls...do you know what neighborhood your hotel is in? I would look at Google Maps, address, and walking directions (you can locate the beach on the maps - I didn't go to the beach during my stay, it's a bit outside the walled city but probably not more than a 10 minute walk or so).
https://www.inyourpocket.com/dubrovnik