I can not connect to wifi with my iphone.

Take a look at this Apple Support article:

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

Reset your network settings.

Settings - General - Reset - Reset Network Settings

Reset your device. This won't delete your data stored on the phone.

• Press and hold the Sleep/Wake button
• Press and hold on the Home button
• Keep holding both buttons until the display turns off and back on with Apple logo on it.

Alternatively, you may go to Settings - General - Reset - Reset All Settings

https://support.apple.com/en-us/HT201559

Have you tried turning WiFi off and back on?

Have you tried a reboot by holding both the power and home buttons until the apple logo appears, about 10-40 seconds, then release both buttons?

If this is your home WiFi you can power down the router, disconnect power to it so it is fully shutdown, turn off the iPhone and all devices, power up the router and give it about ten minutes to capture a new starting IP address and stabilize, then one at a time turn on your devices.

same problem can't connect i phone 6 plus to iMac..yes i reset phone..nothing got a real answers or is that just the standard apple support rob response???

starting to think apple is not worth the trouble

this is what is happening to my phone reset setting then try if still not then reset ny using home button n sleep and awake button