In school, we learned that in interrogative statements to use do (e.g. Do you want to go there?).
I'm wondering if there are any cases when do is not required.
For example, I'm thinking if this is this correct: Want to learn to code? I may help you.—meaning that if the asked person wants to learn programming, it could be possible that I'm available to teach her/him programming.
So, what is the difference between Want to learn to code?/Want to code? and Do you want to code?
Also, how can this be this question changed to have the same meaning, to be correct but still friendly and informal (e.g. it should be something that can be posted on Twitter)?