Camera and Photos apps.
Turn on the Grid for taking pictures. Open Settings > Camera > Grid > ON.
Now the Grid is visible when using the Camera, align the horizon or straight lines to a grid line. The grid lines will not be recorded with the photo.
A fun thing to do with photos is to set your device Wallpaper for the Lock Screen or Home Screens. In Settings > Wallpaper > Choose a New Wallpaper > ... choose from Apple images or from your albums.
Photos can easily take up both device storage space or iCloud storage space. Keep track of both --
Settings > General > About > Capacity and > Available
Settings > Apple ID > iCloud > Manage Storage used GB of subscribed GB storage plan
Review the User Guide chapter on Camera to see what the buttons do. Naw, just press every button to explore the options! If a button color is yellow then that function is active/on. Review your screen to be sure your Flash and Live buttons are white, or turned off. Another button is the Timer, when active it will delay the exposure and take several images as a Burst.
Don't let the camera make the decisions for you! Open the camera, set landscape or portrait orientation then touch the screen to set the focus on your subject. You will see a yellow box appear with a sun icon. Slide your finger up or down the screen to change the exposure. Yea! You are in control.
Another type of image that is soooo helpful in using your iPhone and iPad is taking a Screen Snapshot, a picture of what you see on screen. This varies by device model, but usually entails touching two buttons at the same exact moment, the Wake and Home buttons or on iPhone X the Volume Down and the Wake button. Practice searching the web using Safari and type your question like this "make a screen snapshot on ipad"
After you take a picture it will appear in the Photos app. Again, touch every button to see what they do. Read the Photos chapter in the User Guide. Photos has different views that might take practice to master. A powerful feature in Photos is to Search by location or date or subject. An example of search using Artificial Intelligence is to type "cat" or "dog" in the search field. How about "beach" or "flower" for additional practice.
The Albums view in Photos includes automatic albums and custom albums that you make. There are many things to see here, Swipe from right to left and from bottom to top to see more. Some automatic albums are listed as text (iOS 12 & 13). Look at the number associated with Bursts, Live, Video and Snapshots. Important here is the Recently Deleted album. Photos deleted remain in this album for 30 days and then they disappear forever.