YouTube will probably look something like this when you first go to it.
Step 1: Open the Side Menu and Click Library
You'll possibly need to open the side menu by clicking the topmost highlighted box. Then you can click on the word Library to be taken to your playlist library
Step 2: Click New Playlist
Step 3: Give the Playlist a Title and Click Create
Step 4: Click on Playlist Settings
Step 5: Ensure "ordering" Is Set to "Date Added Newest" Then Click Save
Step 6: Click the Add Videos Button to Add Videos to the Playlist
Step 7: Finally Select the Tab "Your YouTube Videos", Select the Ones You Want to Add and Click "Add Videos"