Not sure if my UML USE-CASE diagram is correct

I've started learning UML but it confuses me sometimes (for example what i'm allowed or not to put in my USECASE diagram, last time i was wondering if logging in can be used in usecase diagram). Anyways i've made simple usecase diagram of e-learning platform, like lynda but you have to pay for individual course you'd like to take. Any suggestions/corrections about my diagram? (i'd like to bring more usecases into it)

I would split that Usecase called Register/Login into two separate Usecases. I think these steps are two separate actions and need different steps to execute. This way you are also able to transform the Usecases to Composites.

We often do it this way:

• Create the Usecase
• Create an Activity Diagram with the same name
• Right-click on the Usecase
• Advanced
• Make Composite

Then you could add more detailed steps on how to implement/execute the certain Usecase in the Activity Diagram.

This answer is specific to Enterprise Architect of course.