Why would you want to do any specialized training at this point? If you are progressing with two runs a week, then it seems to me there really is no need to do anything else beside it. Enjoy your runs!
You might want to consider doing one of your weekly runs short and fast(er), and the other long(er) and slow. This way you vary your training during the week, giving your body more stimuli to improve performance.
As others have suggested, interval training comes on top of the bulk of your training, which should be at a leisurely pace, mostly, with some moderate accelerations during those runs. In my opinion you need to do at least three weekly training sessions before even considering anything else than just running a certain distance, roughly at a constant and appropriate speed.
However, there are other approaches (as there always are). For instance, by doing extensive intervals with walk breaks (in the beginning, slow paced running if you're more advanced). However, these all assume you already have a race result, giving you a target running speed between the breaks (which "breaks" are the "intervals" in interval training, BTW). You do these extensive interval training sessions instead of your weekly runs, changing your training method altogether.
There are several possible variants to this approach, but discussing them doesn't really answer your question, I guess. You may want to know about those anyway, so that's why I mention them. If you are interested, look into the run-walk-run method by Jeff Galloway and the Verheul method by Dutch running coaches Klaas Lok and Joost Borm.
I'm sure there are many more similar approaches, and knowing about them is good, even if you don't plan on using them at this point. It puts things into perspective, and more knowledge about your favorite subject is good, never bad.