There seems to be quite a bit of misconceptions going around about Christianity that are absolutely false, so I will be listing them here.
Please note that I am totally not attacking anyone who may have thought this or thinks this, I am just pointing out the facts.

Number one, you go to heaven if you do good things.
That is against the core of Christian doctrine, you go to heaven because of the grace of Jesus Christ and belief in Him. Christianity is by faith, not necessarily faith alone, but by faith; Christianity is not a religion of works like Judaism, and it is not salvation by works like Islam, it is clearly the outlier of the three because it is salvation by grace, and it emphasizes that faith precedes works.

Number two, Christianity is anti-science.
People often talk about how the Church persecuted Galileo for teaching heliocentrism and that we all believe the Earth is almost 6000 years old, pointing to Christianity being anti-science which is, in fact, insane to actually think. Christianity is actually very pro-science, having created the first universities and essentially inventing our modern scientific method. Galileo wasn't thrown in prison because he taught heliocentrism, in fact he was just expanding on what Nicholus Copernicus theorized. Nicholus Copernicus was an astronomer and devout Catholic. Galileo did teach heliocentrism with the Copernicium model, but he often taught it as fact when he had no evidence, so the Church ordered him to stop teaching unscientifically and he even agreed to it, but when he disobeyed an actual court order to stop teaching unscientifically, he was placed under house arrest in Florence under the care of his daughter.

Number three, blind faith.
Christianity is often attacked for the followers just having blind faith, believing in Christianity without question or proof.
This is false, Christians are supposed to expand on their belief and not just believe blindly. The Judeo-Christian book in the Bible, Ecclesiastes, is about questioning if the faith is true, and the author comes to the conclusion that you cannot live without the faith. The truth is that Christians may not have that one piece of proof that debunks everything except Christianity, because faith is about trust and trusting everything that we do know for certain.

These were the three common misconceptions about Christianity that I have found to be most prevalent, if you have any slight corrections or wish to expand on what I have said here please feel welcome to do so, I am always open to help!