Time to back up a whole bunch of steps. There are 2 basic homebrew routes.
1) Buy extract that a professional brewer has mashed, boiled, and concentrated into an easy to use form.
2) Buy malted grains and conduct a mash like a professional brewhouse would.
#2 is not rocket science, but it takes some equipment and knowledge. You can't just toss the grains in a pot like you do extract and then boil them. All that will get you is barley tea.