It wasn't "solarpunk" at the time, but I am vegetarian now for 15 years ish (since my early 20s). I do think better would be to go vegan and I have been trying to reduce dairy, but it's a bit tricky since a) we also have a small daughter and nutrition is such a complex topic for her as well and b) my wife while having gone veggie due to meeting me is not on board with giving up cheese. It is something I want to tackle more in the future though. I've been mostly motivated by animal suffering and factory farming initially, but ecologically it just makes so much sense as well for climate impact, space usage, water usage, etc.
A small solarpunk thing that I am doing now is choosing regional insect friendly plants for my garden and also learning more about ecological aspects there.
Also while kinda ineffectual, I started editing Wikipedia. IMO shared knowledge building like that is also very solarpunk. It's also some "direct action" that is suitable for a lazy couch sitter like me who struggles to do "practice" otherwise.
Also very much just a point of privilege on my side, but we did manage to build a house and I have literal solar panels on my roof. Not very punk, but very solar wow.