Well, basically what is written on the title, anyone has an idea how the event works on FKG.
is it like aigis with star rush or more of unit farm ?
what is the average lvl to get good results and of course what kind of girls should we expect ?

So far from what i could read it works like a star rush yes.

As for levels, i was recommended to get a full squad of level 30s and then focus on single girls instead. No idea what you need for the star rush completition though, but given that it is a beginner thingie and lasts for 2 weeks i'd assume it won't be that difficult.