Miramar is quite a way from town. I would say about 3 miles, but that is just me guessing. We walk down there most days with our dogs. There are various ways to get to town depending on how adventurous and energetic you are. Walking. We live a little South of Banana Beach and walk to town along the beach regularly. From the Miramar, it would be about a 45 minute walk to town I would guess. As hot as its been recently, I would find the walk to town a bit too much of a challenge unless I stopped at the many bars along the way - for rehydration of course.
Being as far south as you are means you are closer to better fishing. Fishing off the docks can always result in a surprise but once you've been out on a boat here (if you are with a good guide), there is no comparison. The lagoon at the back is great for fishing too, although I would be hesitant to wade in it unless I was in a particularly clear area as there are crocs. There is a barge channel not far from where you are staying that you can fish in from the platform. Good place for cudda.
If you like fly fishing, there seem to be tons of bonefish around and again, down south, you can find them from the shore.
Hope you have a great time!