What is this please help please - Nintendo Video Game Consoles & Games

Have you read the last line of that message. Perhaps that would be a good place to start

I believe online support for previous Nintendo consoles (Wii, DS, DSi) has been terminated. If you're playing Pokemon Black or White or any of the other DS games, online features won't work. Check out the hyperlink for confirmation. Nintendo Wi Fi Connection service for Nintendo DS and Wii has ended...

To put it in simple terms, your Nintendo device wants to connect to the internet, but in order to do so you need to set up a connection under settings> internet settings.