Since it looks like you will be floating a sofa, I recommend that you use a sofa table/low console behind the sofa - to back and anchor the sofa.

And you may also benefit from using a tv mount that can extend the tv and angle it a bit.

Amazon has various articulating arm mounts.

https://www.amazon.com/dp/B08Z7QW5S6?

I have a TV mount like the one @freedomplace1 pictured. It is fantastic. It is very easy to pull out when you want to watch and push back in to place when you are finished.

I never quite understand what coastal design means, however, it would be easy to just paint this current set up all white, remove the shelves and mount the TV in that space. Get new cabinet handles. Hang art above the fireplace. Do something coastal on the right side (whatever that means ;))

If it were me, I’d keep the lower cabs (thinking there is not flooring underneath them but could be wrong) - as suggested pull out all the shelves and then make your plan, I like the pics shared above

Frame TV would give you something nice to look at - from Etsy

It would seem that either area on either side of the fireplace would work well for installing a tv but, of course, will required removing/reworking the shelving in those areas. If you want maximum flexibility for tv viewing you can get a swivel mount to facilitate that. It's a lovely room btw!

Just remove the upper shelves on the right side of the fireplace for the TV.

For coastal feel, start with an abstract seascape above the fireplace then pair it with a new rug in the same palette.

Cool Water 1 Artwork · More Info

Surya Banshee BAN-3342 24x36" Rectangle Modern Wool Rug in Dark Blue/Blue · More Info

"Green Waters Edge II" Fine Art Giant Canvas Print, 72"x72" · More Info

10' X 13' Blue Green Grey And Ivory Abstract Power Loom Stain Resistant Area Rug · More Info

Rustic feel coffee table echoes flooring.

Moore Rustic Lodge Antique Mirror Tray Wood Coffee Table · More Info

Abstract seascape influences furniture, decor choices.

Here's abstract art echoes outdoors so brings it indoors. Rug, pillows, upholstery echo sky, water.

White fireplace; armchairs and coffee table echo art and golden wood floor. Your floor is driftwood color, so choose some of your furnishings with that palette in mind. But start with abstract coastal art in a palette you love and go from there.

Thanks for mentioning a console behind the sofa, freedomoplace1 - I agree it would help tie things together. la_la Girl, appreciate the heads up on the flooring beneath the cabinets….I didn’t think of that! Absolutely love the inspiration that you shared, housegal200! Especially the 1st rug, sofas, and tub chairs! Looks like there isn’t any way to have the TV directly in front of the sofa with this fireplace set up. Thoughts about a sofa with 2 swivel recliners and maybe the recliners could go in front of the TV? Trying to not have to turn heads when watching a movie. Appreciate all of you!

If you install a wood base for the bracket, you can mount the TV in front of the shelves.

Or you can adjust the shelves to receive the TV