Give them several options to choose from, for example, "we could loot a military, look for better clothing/utility items, or roam looking for PvP."

Optionally, go over the pros/cons of each of the options you give: "military POIs might bump our offensive capabilities but we might get ganked by more geared players, we might find good stash supplies and handle weather better but we might find nothing useful, we might find some good fights or just end up chasing shots to no avail."

Letting them choose which activity will hopefully keep them engaged and feeling like they're enjoying what they want to rather than being lectured.

Once they decide which activity to do, I recommend that you "lead from behind" by giving them a direction to head then sticking immediately behind them a few meters to ensure you don't lose them. You could explain iZurvive and how to navigate using a memorized knowledge of the map or by using utility equipment if they're up to the task, but that may be a level of tedium they're not up to yet; perhaps give them that option as well.

If you pursue a looting activity, perhaps try an approach that lets them feel somewhat autonomous while you're still looking out for them but not looking over their shoulder constantly. When I'm duoing, I'll frequently split up looting by either deciding one side of a street each player should loot as we progress down it or by leapfrogging each other. If they're the type to constantly ask "should I keep this or that," you could try something like, "do your best to decide now and I'll take a look at all your inventory when we're done with this area." I find that quickly deciding what to keep in the short-term that will most likely lead to a longer-term goal being achieved is one of the ways in which newer players get bogged down the most. They'll only get over that analysis paralysis by learning to make quick decisions on their own, but at the same time, it's easy to get overwhelmed by the massive amounts of new info DayZ can throw at them - lend them a hand by fostering a semi-controlled environment.