Dynamics Portals Designing and USD

Hi CRM's!!

Myself have been working on Dynamics 365 Customization and Development part. But recently got a new project in my company refers that to do on Dynamics Portals designing and USD related things. Through this, I just went to searching those subject related PDF's, reading blogs, whats app groups, and watching videos on Youtube and all for getting stuff to learn in this part as of now. But I totally become tired!

So, Can anyone kindly suggest me how do I get to learn, what are the main important topics I should be covered and from where I get this portals and USD stuff to start to learn as well?

Looking for your valuable replies (information) and any helpful links to go and watch.

Thank you all in advance!