I'm not an artist, but I think the electronic circuit theme is a pretty good start, as its elements are all really simple visually, I would go all on with it. Either pixel art or vector art would work really for that while remaining quite simple I think. For example, a lootk like this would be neat https://www.shutterstock.com/fr/image-vector/vector-motherboard-illustration-com...
Art is quite hard to nail, but only practice makes perfect. I personnally struggled a lot in the past with pixel art, but I start to make things I'm actually proud of. It just takes time !