Welcome to the forum. And nice user-name

I don't know anything about the CS course you describe - but regarding the youtube link, I usually discourage video for purposes of learning a programming language. Instead I recommend getting a book. Even tutorials are weak compared to a good book.

Also, you should explain the problem you're having and post the relevant code here, using code tags.

You should have a compiler set up on your computer. Do you have one? And if so, which?

A compiler should generate warnings and errors if there are problems with your code. In the future, if your code fails to compile and you don't know why, also post the errors here so we can help you fix them.


Let's look at the do-while loop, since that's what you linked.

Code:
do
{
    /* code to repeat */
} while ( /* true */ );
Notice that the code you want to repeat goes after the "do". The braces are optional if there is only one statement - for multiple statements, they need to be enclosed in braces (to create a "block").

This is a piece from what you linked:

Code:
do printf("please give me a value between 0-23:\n"); 
        }
        v =GetInt();
        {
        while (v > 0 && v <=23);
Problems:

1. You have a statement directly after the "do" but before the opening brace of the following block of code
2. You have an closing brace where the opening brace should be.
3. "GetInt()" is not a standard function (as rstanley already mentioned).
4. You have an opening brace where the closing brace should be.

The loop will continue from the start if the expression after the "while()" evaluates to true. Otherwise, the loop stops and program execution continues from that point.