Please remove the screen and post a picture that is not so blurry from a little further away, straight in front of the fireplace, so we can see the entire fireplace wall floor to ceiling.

a good cleaning with a scrub brush and soap & water... wear gloves.

Will agree that first step is to give the brick and grout a good cleaning. Would not suggest a stiff bristle brush though. Too stiff and you will damage the grout. Wish there were other photos. Hard to give advice beyond cleaning without knowing what the rest of the room looks like.

As noted, please provide additional photos so we can get an idea of entire room for design assistance.

I love the woodwork around the fireplace but it definitely doesn't say beach house. I think of beach houses as being lighter colored and airy. Would you consider pickling the woodwork - that would lighten and change the color but would allow the wood grain to show thru.