my Apple Watch does not pick up to my router

Apple Watch -> Settings -> Wi-Fi

make sure WiFi is turned on

Select your network

Enter your password

https://support.apple.com/en-us/HT209071

If you home network "Hides" the WiFi name, then you will have issues. You might be able to get your iPhone to pass the connection information to your Apple Watch if your iPhone uses Settings -> tap on your name/picture (Apple ID, iCloud, iTunes & App Store) -> iCloud -> Keychain. The Keychain is where you iPhone's WiFi connections and passwords are stored.

Connect your Apple Watch to Wi-Fi

1. Open the Settings app on your Apple Watch.
2. Tap Wi-Fi. Your device automatically searches fornetworks.
3. Tap the name of the network that you want to join. Your Apple Watch can only connect to 2.4 GHz Wi-Finetworks.
4. If asked, enter the password with Scribble. ... 
5. Tap Join.