when you have explained about the risks, and he accepts it, then you are beyond that responsibility. if you still feel bad about it, then stop giving information about trading to him, and tell him to find out the information himself. tell him that when you have started, then come to yourself and share about his experience. However, if you still want to guide him, then try to minimize risk by using a minimum deposit on an exchange to do a trial error in trading. maybe $10 is enough. I'm pretty sure that he will get an idea of what trading really is and the risks involved. However, it's all beyond your responsibility, and you don't need to feel bad about this, in fact, you are giving new knowledge to your friend.
But if he continues to give guidance, I think it is better to do it on demo by teaching him to read the chart because if you deposit $10 while still guiding him, it is still useless. It is better to make him deposit the money and try his own strategy so that he can learn from it. It is really debatable on this, as others don't want a demo while learning as there is no feeling in it, but this depends on what he wants. But for sure, you are still worried right now, so don't give him more advice.