Step one would be to learn enough English to communicate effectively and ask questions that make sense.
She was a librarian before she became a scientist/astronomer
This means a job that someone did before the job that they have. For example: He was a student in physics before he became an astronomer.
became a lawyer
It means student of astronomy. Example: he was a great astronomer.
You would have attend about 6 years of college before you can become a Astronomer.
He was not the first astronomer; there were plenty before him going back to the Babylonians at least. Galileo, however, was the first to use a telescope.
Go to law school, graduate, and work hard
Williamina Fleming discovered thousands of stars and classified them according to their spectra. She also discovered the Horsehead Nebula and many variable stars, fundamentally contributing to the field of astronomy.
I think you mean graduate as in - I have one year to go before I graduate from University.
No, medical school is the graduate school for medicine.
He made his own book (De Revolutions), he became an astronomer, and he died at 70 years old .
You attend and graduate from a college that offers this a degree is a start.