Hi Cathrin - That pointing icon is just an image, so if you have permission to use that image, you can upload it into Unbounce and add it as a new image. Then just drag it to the correct position on your own page. Alternately, the Noun Project has a whole bunch of arrow icons that are free for anyone to use, so you can use something similar from there.
For the Facebook like button, you can create an embed code via Facebook here and the embed that in a custom HTML element in Unbounce.
Here’s a quick video of what that process looks like:
If you run into any issues with the above, please give us a shout at firstname.lastname@example.org, Cathrin, and myself or someone else from the CS team will be happy to troubleshoot for you.