No. You activate with first usage, i.e. when you first insert the pass into a ticket gate. It will then be valid on the day of first use and the following day.

Note that it is only good on Tokyo Metro Lines, not the Toei Lines. Also it's doubtful whether they would sell you 2 passes for each person. You can ask and I would be interested to know whether it is possible too.

Suica can be used on Tokyo Metro, Toei, Yurikamome(monorail) etc. You just need to buy either Suica or Pasumo, not both.
http://www.japan-guide.com/e/e2359_002.html

Thanks for that. Suica doesn't make this clear at all. So as a tourist I can buy a suica card for 3,500 yen at Narita airport, use the narita express to get me to Tokyo station, then use 1,500 yen credit on the metro, inner JR lines, toei lines and the yurikamome line (around Tokyo Bay) or many convenience stores and get 500 yen back (depsoit when I leave)?
I'm just surprised that you can use it on the metro and toei and yurikamone lines as none of their websites mention this and you cannot top your suica card at anywhere other than convenience stores or JR stations - not at Metro/Toei stations.
Sorry to repeat this but just wanted to make sure.