And how do you recommend learning in terms of sequence—later authorities (Acharonim), and only afterward the medieval authorities (Rishonim)?
Is there any commentator you especially recommend learning?

In my opinion there’s no fixed order. I don’t know your background, but without a significant period in yeshiva, it’s unlikely you’ll manage with the medieval authorities (Rishonim) and later authorities (Acharonim).

Sorry for going on and on, but that’s exactly why I’m asking—because I don’t have a yeshiva background, but still, while I’m in the army, how can I invest my free time in real learning?
For now, the only learning I do is on the weekly Torah portion, with an emphasis on Malbim, and every now and then a little Shem MiShmuel, a bit of Peninei Halakha, and so on, or books of ethics and outlook—Mesilat Yesharim, Michtav MeEliyahu, etc.

I’m familiar with your view that the main learning should be Talmud, and especially how to learn it.

When it comes to the Talmud, I still don’t really know how to approach it, and so I avoid it completely. So if you do have some advice or a particular way that would be good to start, I’d be deeply grateful..

I think that without a framework and without background, Schottenstein is the obvious solution. I’m not personally familiar with it, but it has a translation of the Talmudic text and analytical expansions.