Great Q! I'm a designer (and dev) - knowing dev has helped infinitely with being able to design and work with teams better to implement things realistically and understand complexity. In roles of product design or product manager it significantly changes my work practices and issues when developers have a solid understanding of UX/UI, design systems and design principles (even back end engineers).

Especially if you're interested in design and building things, highly recommend doing a design course online (there's ones made for devs) or getting some fundamentals and theory in through youtube videos and books. You'll grasp it quickly.

For really minimalist sites like yours there are a few things that are exceptionally important to pull it off:

• Your logo (or at the least the type you use for it)
• Your typography (the font, the sizing, case usage)
• Your layout and spacing (padding and margins)
• Your colors
• Your copy (clear, compelling, no unnecessary use of symbols etc)

I made a few changes in the browser console to demonstrate it on your site but looks like I can't attach a image to answer a question. I'll see if I can do it in a reply or to do!

There's a few galleries like siiimple.com where you could take some inspiration to learn.