Mostly debates of Tahwid vs Trinity
I lean towards more christian approach. I am one person, but I know I am made up of smaller parts. Jesus Christ himself said The Father is greater than him, and that he only takes orders from The Father so thats why he told Peter (I think Peter) You have seen me, and yet you ask who is The Father? God is ONE but he has three persons. I have part of my mind saying no this can't be right, but what if it is? Then I think of Pascal's Wager and how I probably have a 33% chance of being right yet I see other people claim they know for sure. I don't think they should have such confidence, or if it is true confidence in the truth, then I do want to know, Jesus Christ said he is The Truth, The Way, The Life, no one goes to the Father but through him. He is the Messiah. The Son of God, yet God incarnate, through Gabriel we know this because he told Mary you will have a son and his name will be Immanuel, translated God With Us. Why would this same angel, Gabriel, who is in the Quran as having the original Quran from Allah sent to be the final religion. No, that angel Jibreel was not
angel Gabriel, because the Quran rejects the Son of God and therefore rejects The Father. I believe that so called angel Jibreel was actually Satan. In the Quran God is supposed to be One. Yet, you can find the verse, Allah changes shape from one that is not recognizable to Muslims, to one that is recognizable in order to get there approval while he was saying
"I am Your Lord." Oh yes, your they're Lord indeed, Lord of the synagogue of satan. I accept Jesus Christ as my Lord and savior and I know he is God incarnate and the son of God at the same time. His sacrifice was necessary because Gods laws never change. Therefore only God himself can change laws. He knew this and tried to make us understand that
by telling the Jews to sacrifice animals for their sins. No longer ist hat sacrifice necessary, because the ultimate sacrifice is God dying for Us. He died unjustly, because the Jews said He is Not God (just like islam is doing now, Paul said the antichrist believes not in the Son of God). This unjustly death to the hands of people deceived by Satan had a supernatural effect.
Thats why Christians say, He Died For Our Sins. He literally broke the old covenant laws and gave believers in him full of Grace and the Holy Spirit to guide in the truth.

So thats what I learned so far.

Should I investigate further about the origin of each religion? I heard some rumors that Islam was actually created by a Catholic. If anyone knows if there is any evidence to that please let me know.

Start your investigation under the assumption that neither are true and go from there.

if you wanna go for an early scientific victory, choose islam. if you wanna go for late game, pick christianity.

The Origin is vastly important. Islam was created much later and under different circumstances, among men trying to survive in savage situations.

The relationship with God in each religion is also a main difference. In Christianity God actually has a relationship and a discussion with man in the fact that Jesus was sent down. In Islam you are essentially a slave ordained to carry out Gods orders.

The train of religious origin generally goes Ancient Sanskrit => Judaism => Christianity => Islam with some odd transitions in between.