So you have an IP address on your mac computer but you can't back up your phone or use the net on your ipad. Start by seeing if you can surf the net on your Mac, if that works, check the network settings on your other devices.
My I-phone, I-pad, and MAC all show that the WiFi is on, and my MAC shows that I am connected to Telus 4900 at 192.168.1.65.
My pad is connected by a hub connected to my MAC, but when I try to use Safari on the pad the message says that I am not connected. Also, I used to get e-mail on my pad until last November. I plug my phone into a separate outlet to charge it.
A few questions.
Telus switching mail providers wouldn't have affected the wifi connection itself on your devices. It sounds like Telus4900 may be the wireless network name. If it's still asking for a password, assuming it is your network, that will be why your iPhone and iPad aren't connecting. Find the router that Telus installed in your home. There is usually a sticker on the side of it that shows what the default network name and password is.
On the wireless network list, the 🔒 icon indicates that the network is secure / needs a password.
If Telus4900 is the correct network and your iPhone and iPad used to work with it, in Wi-Fi settings, click the "i" symbol to the right of the network and in the following screen tap Forget This Network at the top. Then choose your network again and enter the password. If you do not know the wireless password, you can use the Telus My Wi-Fi app to view and change the password. Alternatively, you should be able to log in to the router from your computer that has internet access.