talk to the team galactic guy in front of the team galactic building.(In veilstone city)
the galactic key is in somewhere in the game N.M.I
You will need Galactic key and this how to get Galactic key you will need to talk to a Galactic team mate by the Galactic HQ.
At the end of the Galactic warehouse
When you go to the team galactic veilstone building there will be a galactic grunt and you talk to him then he'll run away and he accidentally drops a key.
In the galactic warehouse to the left of the Galactic HQ
go to galactic headquarters in veilstone city then you need a galactic key and the storage key to open the door of team galactic's door
you go to the team galactic ware house
its in the galactic ware house in velistone
u catch girantina and then after that you go to veilstone city and go talk to the team galactic person in front of the galactic warehouse I think galactic warehouse it is one on the team galactic places in veilstone city and then he will go somewhere and drop a key which it will be the storage key. Hope this helped and sorry I cant think of the name of the team galactic place it is the biggest building of the team galactic places (in veilstone city)
after you get galactic key go to the HQ with sattilite dish go to the door
you get the special key through the mysterygift