[quote=@Sublimation]
Also about the master spot then would I have to play as a magical girl?
Or is it that spots are currently unorganized and therefore its unclear as to whether I will have to regular master or not?
[/quote]
Currently, the spots [i]are[/i] unorganized, but as for the master spot, no, that has nothing to do with playing a Magical Girl, since Magical Girl Servants, as the phrase implied, are Servants. They are not Masters nor could they become one. The details behind this is explained in the official codex once it is up, but just know that it involves Kyubey turning Magical Girls into Servants, though not necessarily Heroic Spirits.

Therefore, out of the six Servant spots, two of them must be Magical Girls.