How to differ release and debug?

Question

I use codeblocks, and as the lesson says I use codeblocks and creat a project named "sololearn", then I creat a new file and begin to compile, but when I build and run, it have some errors, one of them is "error: redefined 'main'".
And other question, how to choose about "release " or "debug" when I creat new .cpp file

Answer 1

cant help if cant see code