Anis Rehsaet

Allah is simply the Arabic word for God. Arab Christians (as well as Muslims) use the word Allah to refer to God. Muslim and Christian understanding of God is very similar. God is good, all-knowing and all powerful; He is the creator of the universe, the beginning and end of all things. But there are also differences; most notably that Muslims don't believe in incarnation (God became man).

My understanding is that unless your father is a Muslim, he cannot be your wali. In the absence of a wali, the leader of your Muslim community or mosque can give you in marriage to the man you wish to marry.