You can no longer connect to Nintendo's online services on Wii. The Wii Shop Channel (purchases, downloads, WiiWare, Virtual Console) shut down on January 30, 2019. WiiConnect24 (standby messaging, Mii sharing, data exchange) was discontinued earlier.
Upgrade to Nintendo Switch for active online services (Nintendo Switch Online), huge library, and continued support.
The Wii had a great run. Enjoy its legendary local library, but don't expect online.