How do I create a new folder on my iPhone

What kind of folder are you attempting to create. The type of folder will help define the method to create it by. The last poster describes how to create a folder in the Files app. If you are just trying to create a folder for your apps on the home page, just touch and hold one of the apps you wish to put in this folder and the drag it over the top of another app you wish to have in the folder. That will create a folder, give it a standard name and the two apps will be in there. From there you can add additional apps if desired in the same manner, by pressing, holding, and dragging to the folder. You can edit the name of the folder if you wish by putting the page into edit mode by pressing and holding until things begin to wiggle.

If you are referring to something else, please provide more details.

First open the files app on your iPhone. Then from the iCloud Drive page click the three dot icon in the top right corner and select New Folder. Once clicked you can name your folder and you’re finished.