How do I find history on my computer that has been erased?

Honestly you can't.

How to look at erased history on computer

First, may I call your attention to the guidelines for using the comments feature found here:

https://www.askmehelpdesk.com/feedback/using-comments-feature-24951.html

Sorry but Ben is correct. You can check the recycle bin, but generally a purged history is gone. It MIGHT be recoverable with expensive professional tools.

I suspect you see TV shows and movies that show cops finding an deleted e-mail on someone's computer and think everything can be recovered, but the truth is once deleted the potential for recovery is small.