I think there's a ton of benefit of spending time in communities that center around learning and intentional relating. You could look at the Global Ecovillage Network or www.numundo.org.  I also would promote designing your own learning journey based around a project or research question and using that as an excuse to network with amazing people and hopefully offer them some useful synthesis in the end. I think designing something that centers around a research question thats important to you will lead you to pursing things enthusiastically and actually following through. It's not typical 'volunteering' but when I've done things in this spirit it's led to some amazing unexpected outcomes with rippling effects.

I imagine the kinds of volunteer work you can do in your home country are less likely to be harmful in a foreign country. For example, in my home country I've volunteered picking up litter, painting houses, running children's events, etc.

I don't expect it to be "effective", but it doesn't sound like that's the main reason you want to do it, and that's okay!

Would you be interested in supporting EA groups abroad to recruit local talent to work on impactful causes? I'm not sure what country you're from or what languages you're fluent in. But even if you only know English, it seems like you could potentially help with EA Philippines, EA India, EA University of Cape Town, EA Nigeria, or EA groups in the UK, US, and Australia. You can browse groups and get in contact with them through the EA Forum.

To get a sense of why this could be valuable, see "Building effective altruism - 80,000 Hours" and "A huge opportunity for impact: movement building at top universities" (especially relevant to groups like EA Philippines which are focused on supporting university groups).