Hi, and welcome to OpenStreetMap! Since you requested a review, I looked over your changes here. Looks good overall! I do see a couple of problems. For tags like material and colour, the values have to follow specific established conventions. If you aren't sure what's allowed, you can click the "i" icon next to the tag field, and link to the wiki. When trying to list multiple values, you have to separate them with a semicolon, e.g. wood;plastic. However, it's generally considered best to avoid multiple listed values whenever possible. So in this case I'd recommend choosing the more "primary" material of a bench (what material would someone be sitting on?) and use that value only.

Other than that, everything else looks good to me! Let me know if you have any questions, and thanks for your contributions!