Learn English – Single word for lazy student

It might be a little old-fashioned but I think "courting" is probably the most appropriate choice. You might prefer (the also old-fashioned) "wooing".

Jack of all trades is the term that immediately comes to mind. Very common: check. Doesn't connote that the person in question is particularly good at any particular trade: check. In your case, "all" just happens to amount to two, which is not a problem and would be perfectly clear from context.

Edit in response to your comment: Jacks of all trades is fine. And of course the more constraints you keep considering, the less likely it is you will get a result that's less weird, or indeed that you get a result at all.

That being said, since you are aiming for a single-word agent noun, all you need to think of is a verb to derive it from. You have viewer for people who view, listener for people who listen, and so on. Now, since you specifically didn't mention what the other type of activity was, we can't think of a verb that would mean "view + the other activity", but have to go with a very generic verb for "doing more than one thing at once". For which the most common word in my book is multitasking.

So your single-word agent noun would be multitasker.