You can use Multitasking to work with two apps at the same time.The Dock lets you instantly open and switch apps from any app you're in.
To see the Dock while you're using an app, swipe up with one finger from the bottom edge of the screen. If using the Brydge Keyboard the shortcut "option-command-d" will bring up the dock.
This is a good article that explains everything here
Here are a couple of Apple Support articles:
Multitasking: https://support.apple.com/en-us/HT207582
To have two separate web pages open at the same time: https://support.apple.com/en-us/HT207522