I finally managed to bring my portfolio site online. I found it very challenging but it was a great experience. As a trained graphic designer, I really had to get used to tackling problems systematically (or spending lots of time with trial and error). My learning journey felt a bit like a scavenger hunt, whenever I solved one riddle, a new one popped up. Taking breaks helped a lot to think properly about problems before trying to solve them.
After some evaluation, I chose to build it in React with Gatsby. All in all, it was very useful, especially because I found a well suited starter code, but I found it also quite buggy (esp. for some parts I coded in P5 and the CSS after build) and spent some with but fixing. Luckily, its well documented so after finding out what the problem was, I was usually able to solve it quite quickly.