If you could figure it out and do it well, I see no issues with not knowing it initially. I wouldn’t directly lie or pretend though. If they tell me go do XYZ, I’ll go and try and if I can’t figure it out then I’ll say I did try but it doesn’t look right, I might need some help. I don’t see why you’d get in trouble for not knowing something. What can they do to you? Nothing really

I personally prefer to be in trouble for not doing or knowing something and being honest about it rather than being in trouble for pretending I have the knowledge and then being caught.