you need to start thinking like a programmer. Which is a problem solver. the program needs to accept a number and figure out if it is positive or negative.
so to start with the program needs to assign input to a variable(perhaps a prompt for input first), then it needs to figure out if the variable is equal to zero, higher than zero, or less than zero. Then print out a message to screen. <--- there's your pseudocode.
with each program you write you MUST think about the problem to start with, write it down as pseudocode if you must just as I did there.