Hello dare2dance, welcome to this forum!
To post an image you need a hosting service for your images like Photobucket (paid) or picr.de which is in German but free and very easy to use. There are more but I don't know them all.
There is a Questions and help page here where you can find lots of information on how to add images, videos etc. here is the 'adding images' page:
viewtopic.php?f=3&t=21