Terraria - Editing Source Code - Help Thread

Hey, I'd also like to start making a terraria client, I have the latest OpenSource version of Terraria, I have all of the files, I just don't really get what to do with them.

You should probably give up if you do not even know what to do with those files...

That isn't really good starting with something if you don't have any knowlege what what should be.
It is like, being in the US, you will know Burgers, Cola, Milkshakes.
Well, go to japan and you will recognize nothing. They are eating stuff which you won't even say "that thing over there was a fish!" ...

First of all, you should learn some basic java programming, like few have had it at school, or watch some tutorials on youtube.
Even reading some introduction on windows visual basic won't be wrong.

No I didn't mean it like that, ive got the source in Microsoft Visual C, problem is After loading the source It wont find the steam appid

Visual C? or Visual C# Express
C != C#
Then delete all Code Parts where it ask for the steam api / appid

I wouldn't recommend you learn to code by editing a game, start off with some tutorials of c#.
When you know the basics, I can help you understand how to mod terraria, how terraria works, ....