ANSWER:

Istekhara is not done to decide between two different things. After you have made up your mind about something then istekhara is prayed to seek Allah’s counsel whether this decision is good for you or not.

It is not permissible for a woman to travel without her male mahram. 

I am confused if I should wait for the interview from a company or I should go to another city and look for job. For this reason can I pray ishteqaara 2 units after isha and wake up for tahajjud since I really want that job and ask allah swt for that job