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If there was an assault with no weapon then the charge is assault and they might through in Battery for good measure. It is also possible they could be charged with conspiracy to commit murder or maim or intent to injure, whatever charge the minor has pending. There also may be a "contributing to delinquency of minor" charge. It really depends on how hard the DA wants to throw the book
But to get a conviction on a conspiracy, the state will need to prove beyond a reasonable doubt that the friends knew of the minor's plan to get the knife, and/or encouraged him to do the same. If they cannot prove that beyond a reasonable doubt, then it would be assault/battery.
If he was charged with AWD, then the others should be charged with the assaults they were doing before the stabbing, unless they had a dw in their possession
However, as I stated, there are a number of charges that can be placed it is up to the DA to decide how they will be charged. It is possible they can be overcharged and then a plea will be offered to take some of the charges off the table.
Lawyers can be referred via the CA Bar Association at this link.