To Share a post, go to that post and click on the Share button at its top right corner. This will bring up a number of icons representing other social media sites that you can share it to. To Reshare a post, click on the red thumbtack button at the top left, which will let you repost what you like with a note at the bottom noting its original source. Keep in mind that you can prevent others from Resharing or Repinning your post by toggling that option off under the Advanced Settings section when you create that post. This is generally the reason if you find that you cannot Reshare someone else’s post.