Hi @Khalidology,
In addition to the reply by spuluka, I suggest you two more places where you can find extensive material not only on Networking concepts in general but also from a Juniper perspective.
If you can get the subscription to the sites below, you will get a lot of resources to build yourself strong in the field of networking.
1. Safari Books, https://www.safaribooksonline.com/
2. Lynda, https://www.lynda.com/
This opens your gateway to accesssing text-books, video books, tutorials on a lot of networking concepts like MPLS and Juniper specific concepts on JunOS which is the Operating System that run on a wide range of Juniper products.
The courses here deal in elaboration on Networking concepts and this is worth a try if you want to gain conceptual clarity and master them.
I suppose this helps you streamline sources to pursue your interests in the field of networking...