Hi Meagan,
the syntax was wrong.
Plot[4 Sin[x], {x, -Pi, Pi}]
will work.
Built-in functions start with a capital letter and the argument of functions goes into square brackets.
Your way of writing the command does not follow that standard notation, but if you type in an equal sign before everything it will interpret your input and show you the correct syntax as well.
Cheers,
M.
