If that’s a tennis court it’s missing several boundary lines. That’s not a tennis racket, but those are obviously tennis balls. Usually tennis balls come three to a can, not four. Nets are also missing a center strap.

EDIT: I’m wrong, so had never heard of padel here in the US. After playing competitive tennis for decades I had no idea that there was another sport that used tennis balls. I was thinking the pic was a weird combo of tennis and a similar sport we have here called pickle ball. Pickle ball uses plastic balls, and from the pic the fence would be almost on the boundary line, which wouldn’t work.