The five pillars are the shahada (testifying that there is no god but Allah and that Muhammad is His Messenger), establishing the five daily prayers, giving zakat, fasting the month of Ramadan, and performing Hajj for those able to do so. The Prophet ﷺ named these as the foundation upon which Islam is built.
References
Sahih al-Bukhari 8Sahih Muslim 16
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.