Is it necessary to study in a Madrasa to gain Islamic knowledge?

For the past few days, I have been considering studying Islam in depth. I have a strong desire to become a scholar—such as a Sheikh, Mufti, Maulana, Mu’allim, or Allama—following in the footsteps of renowned scholars like Nasiruddin Albani, Zakir Naik, Taqi Usmani, and Mufti Menk. At 28 years old, I have decided to dedicate the rest of my life to the field of Da’wah, but I want to first acquire proper and authentic knowledge. Being born and raised in a Muslim family, I have a basic understanding of Islam, but I feel that it is not sufficient for effectively spreading the message of Islam. Currently, I have limited knowledge about prominent madrasas and little to no connection with Islamic scholars. Is there a way for me to study Islam on my own, or is formal education in a madrasa necessary to achieve deep Islamic knowledge?