If it seems like your iPhone or iPad cannot connect to the Internet to get new information or save your changes, there are a few things to check.
1. WiFi connection
If you're in range of a WiFi network, make sure you're connected to it. You can double check by going to the Settings app: if you are connected to a WiFi network, its name will appear next to WiFi.
Some WiFi networks may appear to be connected, but not actually work until you sign into them via a webpage. If you think this is the case, open the Safari app and try going to a normal website, like google.com. If the expected website appears, you're good to go. If not, try following the directions on whatever website loads instead.
2. Cellular connection
All iPhones have cellular connections. Make sure Cellular Data is turned on in the Settings app, and that your data plan with your carrier is active.
Some iPads have cellular connections – if yours has a rectangular plastic antenna on the back, along the top edge, it can. However, you still have to set up a data plan with your carrier and make sure their SIM card is inside your iPad. You can check your data plan in the Cellular section of the Settings app. You may have to call your carrier to set it up.