schon means something like already, but it can't always be translated literally.

Wenn wir schon putzen, dann richtig.

If we are already in the situation of cleaning, then right/properly.

If we are going to clean, let's do it right

There is an idiomatic expression "Wenn schon, denn schon", which means something like "If we are already at that point, let's go all the way"

je nach means depending on

je nachdem, ob... means depending on wether...

Je nachdem. means It depends. (idiomatically)

denn je means than ever before (As in, I'm healthier than ever)

In the last sentence, it is an abbreviation of jeweils, which means each or respectively

Schreiben Sie je zwei Sätze mit den Redemitteln

Write two sentences each with the rhetorical figures