Does FCP have arrows or callouts that are internal

You find it in the Generators browser, in the Elements category. Drag it to the timeline.

In the Inspector, change from Circle to Arrow:

You can also change the colors, etc.

Then use the Transform tool to scale, move and rotate as desired.

Not in FCPX.. But in Motion, so you can create some effects in Motion and send it to FCPX.

Or take a look to www.FxFactory.com. The Ripple Training Callouts have a lot of things you want.

Have a nice day!

You have arrows in the built-in Shapes generator.

Just add the generator to you your project and in the Inspector change from the default (Circle) to Arrow. It is relatively basic, as s generator it only offers you choices for color of stroke and fill. You can use the normal transform tool to alter the arrow’s length, width, location and rotation.

Once you make one to your liking it is easy to copy and paste somewhere for reuse.

Of course the already mentioned Ripple Callouts offer all sorts of possibilities with professionally created designs and immense customizability. But you asked for something simple, so I’d start with Shapes.