I'd take 800mg of ibuprofen a couple hours before the session. Helps minimize pain and swelling.
Try pure aloe immediately after the session, and dab face with an icepack for an hour. The aloe is important in providing some measure of protection until the body starts closing those pores automatically. The ice provides pain relief and again helps with swelling. Overall redness should be gone in a couple hours, though individual points of red will persist for several days.
At the 2-hour mark, wash your face with something gentle, liberally apply witch hazel (a mild astringent that tightens up your pores enough so bad things can't get in, but old crap can still get out), and lightly moisturize to keep your skin from drying out. This becomes a once-daily regimen. Don't exfoliate for at least 48 hours, better to wait 72, until most of the bumpiness is down.
Absolutely don't touch your face the first couple days (except when washing, after thoroughly washing your hands), as your fingers can harbor bacteria and you don't want that getting into those open follicles.
And of course, if you feel the hairs tugging as they come out during your sessions, your zapper isn't killing the hairs, just plucking them, so make sure that isn't happening.
