SECOND CONDITIONAL

The second conditional has two main uses: 

1. We can use it to talk about things in the future that are probably not going to be true. Maybe I'm imagining some dream. (e.g. If I meet Billie Eilish, I would faint.)
2. We can use it to talk about something in the present which is impossible, because it's not true. (e.g. If I have his number, I would call him.)

https://7esl.com/second-conditional/

Explanatory Video

Practice
For extra practice on second conditional explore this site.