How can one learn about Islam, what steps can be taken before embracing it, and can an Orthodox Christian visit a mosque and speak with the Imam after prayers?

We praise Allah for guiding you to Islam, which is the greatest blessing, and we ask Him to grant you steadfastness. Islam is obedience to Allah and worshipping Him alone, without any partners, for He is the Sole Creator, Provider, and Disposer of all affairs. Therefore, He alone must be worshipped, as Allah Almighty says: ﴿Say, "Indeed, my prayer, my rites of sacrifice, my living and my dying are for Allah, Lord of the worlds. No partner has He. And this I have been commanded, and I am the first of the Muslims."﴾ [Quran 6:162-163]. Islam is built upon five pillars: bearing witness that there is no god but Allah and that Muhammad is the Messenger of Allah, establishing prayer, giving zakat, fasting Ramadan, and performing pilgrimage to the House (Kaaba). The prophets and messengers, the last of whom was Muhammad (peace be upon him), came to convey the law of Allah and to invite people to worship Him alone. None of them ever claimed to be a god or the son of a god. As for the Christians' claim that Jesus is the son of God or a god, it is false and contradicts both reason and scripture, for Jesus and his mother both ate food and needed it like all human beings, and God is far removed from such needs and deficiencies. To embrace Islam, it is sufficient to utter the two testimonies (Shahadatain): "I bear witness that there is no god but Allah, and I bear witness that Muhammad is the Messenger of Allah." This erases all previous sins. You are not obliged to declare your conversion to your relatives if you fear them; rather, you are permitted to conceal it, following the example of the Companions.