Hey guys, I’m looking for some robust plywood that I can use for building. One of my uncles told me that it’s a good material, but there’s a lot of different brands and stores that I can’t choose from, so I need some help.

One of the best options is regular shuttering plywood, since it has desirable properties for building and doesn't cost a lot. You can get it on https://sheetmaterialswholesale.co.uk/sheet-materials/softwood-plywood/shuttering-plywood/ without overpaying, so navigate there if you want to order some plywood. There's a lot of various size options there, so it shouldn't be hard to find what you're looking for.