How to find volunteer work in another country
You're going to have a very hard time finding long-term volunteer work in a first world nation as a foreigner. The main reason for this is their immigration process. In general an organization (including NGOs) must attempt to hire locally for a position before going international. There is also a larger expense for the hosting organization to bring you in as an foreigner than to hire a local (visa expenses, etc).
The exceptions to this would be if you were already engaged with an international NGO that had a project in one of your desired countries that you could work with. In general it is a bit easier to move around employees than it is to bring in a new foreign hire. There may be some flexibility if you can self-fund your volunteer work and then receive a visa as a long term visitor - but these are very restricting visas which do not allow you to work in any capacity for pay (and most labor laws in Canada, USA, and New Zealand would consider free accommodations a form of payment).
In addition your post states that you are not skilled. Unfortunately if you truly are unskilled your chances of making this work are nonexistent. Every country on the planet already has enough non-skilled workers that could take the position instead.
You might want to try looking for immigration groups around your country of origin, or other issues that your nationally would give you some benefit. Yet this is a bit of a long shot.
Try checking out online platforms for volunteering. You might even find some that include accommodation. Here's one for USA: Explore - Xploreo