the waves look nice, but you can improve your photos with some deliberate changes> composition
too much water. the subject is unclear, is it the couple? the sun? the waves? (you probably don't know either). pick something, then rule of thirds. if you showed me the top half without the sun, I would just tell you it's a picture of carpet.
did you take the picture from higher up? get lower to center the water "rectangle" and horizon in your frame> lens
200mm is not good for this shot. 70mm+ is great for portraits, i imagine you used this lens because you were already taking those shots and it was convenient. it's likely why you couldnt line up the shot right. environmental shots fare much better <70mm
wider angle lens, framing the couple in the left third and looking at the horizon is much more interesting composition> camera settings
2000 ISO is way too high, you have plenty of light to work with, so you're just losing color information. set your iso first, 100-800 here
shutter priority here is a mistake, you arent capturing specific motion. when light is abundant, like in outdoor shots, you should be in aperture priority to control depth of field. but doing that here would just highlight the composition problems
if the intent is silhouette, you should look for an exposure that makes the couple/beach completely black. color information in the foreground is unnecessary to the viewer
spend 30 minutes learning the exposure triangle and you'll improve drastically> post
horizon isn't flat, you should fix that in lightroom.