When you watch tutorials , make notes and revise them. Otherwise you will forget everything after 1 or 2 weeks. I know many of you may think that making notes of computer related tech is a taboo but believe me it is not. It is better than watching tutorials again and again.
Now you can take notes either in notebooks or in computer itself. You can make notes online also. I make notes in repl.it (there I use markdown language to make notes).
Now even if you start learning many techs simultaneously , you don't have to worry because you are taking notes of everything. You just have to revise them before you start from where you have paused. Once you have finished the course , then revise the notes at regular intervals otherwise you will forget everything and whole point of taking notes will be pointless.
Key thing is revision, now it's upto you how you want to revise either from your notes or again watching tutorials.
One should actually try to learn one thing at a time,because you will finish it early.
P.S: All tutorials are not good and they don't cover everything in depth. So before starting your learning process find a road-map or make a one.
Summary: Take notes of anything which you are learning and revise them.