how can I go to Temple of the Queen of Heaven & Baxian Mountain from Nankai University east gate?

You can take public bus no. 658 at Balitai Station, get off at Beichengjie Station.
Then walk southeast around 450 yards to get to the first scenic spot.

To the mountain, you can take subway line 3, get off at North Railway Station, Exit C. Then take a train to go to Jixian County first. It takes around 2 hours on the way. After arriving, take a taxi or hire a private car to get to the scenic area.