Is it alright to marry a non-religious person just to please your parents, but you are forbidden to instruct her in Islam, its obligations and prohibitions? In other words, she can do as she pleases, but I practice, or is it better to disobey my parents and find a practicing Muslim woman? What does Qur'an and Sunnah advise?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is not obligatory for the son to obey his parents in marrying a righteous and pious girl, let alone a corrupt one as mentioned in the question. Anyway, if you want to obey your parents in marrying this girl, you must protect her from indulging in what is forbidden and order her to perform her duties. This is the meaning of guardianship. Allah Says (what means): {Men are the protectors and maintainers of women.} [Quran 4: 34]

Our advice to you, dear brother, is to marry only the pious and righteous woman as this woman will be the mother of your children and their first educator. So, their integrity and honesty result from her teaching and example and the religious woman is driven by her faith to the good and appropriate ethics and behavior.

Allah knows best.