I am new to PS and I am trying to add a picture to a shape that I drew with the line tool. I used Create a Clipping Mask to clip the image inside the shape but it didn't work, my image disappeared. Does anyone know how to fix that? Thanks.
Either Fill opacity for your shape is set to 0% or image which you are clipping is outside of shape area.
Click on shape layer and ensure that you have fill applied, that is visible from the Options bar or from Properties panel.
The next thing to check is position of image. Unclip image and see where is its visible part which should cover shape below or you won't see anything when you clip it.
The problem might be that your shape has no fill. Select your shape and from the options running across the top of Photoshop change the fill from "nothing" to a solid colour.