Hi Annie Skogsbergh. Great collection! In order to start a collection, you will start by selecting the first video you would like in the collection. Below the video you will see "Collections". Click on that. Once you've done that, you will have the option to "Create New Collection" or add to any existing collection that you may already have. If creating a new collection, you will enter a name and then click "Create". You may continue adding videos to this collection using this same process.
I hope this helps. Please let me know if you have any questions.