What does being a christian mean?

I think you are asking these question serious and giving you the correct answer for that which we get from Bible which is the base of all these things.

In the New Testament, as everyone know Jesus came to this world, preached the gospel and made 12 disciples named apostles and all. In the beginning they were all called the disciples and followers of Jesus Christ. But later people at that time find out a single name to call the followers of Jesus. That name is Christian. In Bible it is stated in the Books of Acts 11:26 as "When he found him, he brought him to Antioch, and for a whole year they were guests of the church and taught many people. It was in Antioch that the disciples were first called Christians."

So the answer for your is, being a Christian means to be the disciple of Jesus Christ.
And I will also give you a brief introduction about who are the disciples of Jesus.
Disciples are people called by Jesus.
Disciples are those who obey Jesus.
Disciples are those whose personal savior is Jesus.
Disciples are those who witness Jesus Christ.
Disciples are those who preach the gospel of Jesus Christ.
and so on.
As Disciples are called Christian, I think a true Christian have to follow all these things too.
Hope my answer will be a good help for you.