what are the conventions regarding the use of blanks in C and Pascal Languages?

Answer 1

in C whitespace (blanks) are a delimiter for tokens.
likewise in pascal.

Answer 2

There are none, you are free to use (or not use) spaces, tabs and newlines as you see fit to make your code more readable. Nothing prevents you from writing your entire program on only 1 line (except maybe common sense!). The compiler I believe removes all white space characters before compiling.