How to see 2 open apps on my iPad?

Assuming that your iPad is running iPadOS, you need to explore multitasking.

Key to accessing and controlling multi-tasking is the small “three-dot” multitasking button that is found at the top-centre edge of each App Window. Tap the multitasking button at the top of the slide-over window to expose a menu - from which you can change the window view.

More information about using multi-tasking can be found in this support page:

Use multitasking on your iPad - Apple Support

The iPad User Guide is also a rich source of information about using iPad and its many features. The Guide is available both online using a web browser (such as Safari), or as an Apple Books download:

iPad User Guide - Apple Support

https://books.apple.com/book/id1567104892

Use Split View to open 2 apps or windows at the same time.

click here ➜ Use multitasking on your iPad - Apple Support