what will you do if you get a chance to go back to past

Today I was just reading the post of cryptocurrency in that I saw one comment, the guy told that if I had a time machine I would go in past and grab the bitcoins. So I thought if I had a time machine what should I have done?

As I am a crypto lover definitely​ I would buy bitcoin but apart from that I would quit my school and learn something productive which will be useful in ​the ​practical world. And I​ should not have repeated by mistake.

So according to you what you will do if you get a chance to go back to the past.