At the time of my first raid, I was very confused because I was not familiar with the game, but I found a bear that spawned nearby and lured all the raiders to the bear and made them kill each other. Alternatively, since the apes do not attack allies in the current version if they start destroying structures, we set up walls to encourage them to attack and then deal with them.
If Yona is attacked while you are controlling a 'man', she will be stunned. But she will wake up again in time, so you don't have to worry.