How long will my 5 albino cories swim franticly around the tank?

I just bought 5 albino cories and Ik it's natural for them to swim everywhere when u first put then in there but how long are they gunna do that? Also the store must of had them with tail biters because most of the 5 have like half their tail gone, will that grow back? Will the be fine? And I bought food for them and if it has cories on the front of the package does that mean it's for them? It is called sinking wafers. Also how can u tell male and female apart? If theres more males then females is that a problem?