How do you insert a picture into another picture?

There's no easy way to explain this and no easy way to do it well.

You need a photo editor, of which there are many, and as each one works differently, you need specific instructions for that app.

I would start looking on You Tube for videos that explain and show. For instance:

add faces to a photo - YouTube

Just use any photo editor and go to the stickers option and it should give you the option to use a picture from the gallery. I just did it on the InShot app if the one you’re using doesn’t do it.

By using an external editor:

In order of price here are some suggestions:

Seashore (free)

The Gimp (free)

Graphic Coverter ($45 approx)

Acorn ($50 approx)

Pixelmator ($50 approx)

Photoshop Elements ($75 approx)

There are many, many other options. Search on MacUpdate. You can set Photoshop (or any image editor) as an external editor in iPhoto. (Preferences -> General -> Edit Photo: Choose from the Drop Down Menu.) This way, when you double click a pic to edit in iPhoto it will open automatically in Photoshop or your Image Editor, and when you save it it's sent back to iPhoto automatically. This is the only way that edits made in another application will be displayed in iPhoto.

How's that even possible can you please tell me it's to confusing for me thanks