Instead of having to go to a different keyboard every time you want to add punctuation (or numbers), there is a shortcut for this:
Press and hold on the Numbers (123) button, and swipe over the item you want to include. This will be added, and you will remain on the QWERTY keyboard.
Find more tips on how to get the best use out of your iPhone, in:
iPhone for Seniors in easy steps, 8th edition
Covers all iPhones with iOS 15
By Nick Vandome