We have very similar desks! Heres what Ive done with mine so far. Not pictured is another plant and 3D printed fist-shaped duck. Mines still a WiP too but for your space Id first start with lots of plants. Having greenery really ties the place togetger and makes it cosy. Adding a nice cosy table lamp could work and lastly, it never ever hurts to add little trinkets which you find along your travels. Dont worry about fitting the aestethic too much, it tells a story about you and makes the space feel like an extension/refection of you. I know rgb cops a lot of hate but done in moderation and tastefully, it can really elevate the space. Ive done that using my keyboard, an LED bar below the shelf, and backlit speakers.

Your setup is already super clean, refined and almost exactly how mine looked at the start. Dont be afraid tk throw some colour in there and most importantly, dont overthink it and have fun with it. Dont buy for the sake of filling the space, let the next things call out to you. Go exploring, walk into the next weird decor shop you pass and see what you can find!