Activating 6s plus and can't get wifi connection

How do I activate my phone

Have you forgotten your passcode?, see this Apple article: If you forgot your iPhone passcode

https://support.apple.com/en-us/HT204306

Unlock Passcode -> without a computer.

How to reset your iPhone, iPad, or iPod touch when you forgot your passcode

https://support.applhttps://support.appl

See also this Apple article: How to remove Activation Lock

https://support.apple.com/en-us/HT204051

can't get wifi connection

See the following Apple articles:

Connect to Wi-Fi on your iPhone, iPad, or iPod touch

https://support.apple.com/en-us/HT202639

If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network

https://support.apple.com/en-us/HT204051