If you are departing AMS for MAN then, normally, you would go through Departures 2 and ending up on the non-Schengen area of the airport, i.e. lounge 52. I'd say that in 99% of cases that is the better of the two KLM lounges anyway, so I'd stick to that. Theoretically you could go to the Schengen zone first to try lounge 25, but I see little advantage in doing so.

If you are Skyteam Elite plus you (and a guest) can use the lounge for free, by the way. No need to "add lounge access to your ticket" (Presumably for a price). Your status includes free lounge access.