You will also come across such sentences as: If Andrea was at work, I would prepare the evening meal. Although this has the appearance of a 'second conditional', it is actually referring to a regular past situation.
I dislike the terms 'First, Second, Third, Zero' and 'Mixed' Conditionals. There are dozens of possible conditional sentences that do not fit into these traditional patterns.
Here's just one example: If you heat ice, it will melt. This has the appearance of a 'first conditional' but the meaning of a 'zero conditional'.