2 questions: There is an open Product Owner position in company because previous product owner has left this company

Imagine following situation:

I am selected for Product Owner position but I need your opinion on 2 things:

1. How can I proceed working on product where previous Product Owner was (in the middle of the development). What are the steps to follow?
2. How can I be fully and fastly introduced with this new product so I can start doing my role as Product owner as soon as possible. What are the steps to follow?
3. Also, since I am new in this company, how can I have a future vision of this product and company? What are the steps to follow?

Thanks