Openings

I need to do some studying - particularly openings. I have noticed that when a new tournament starts I may have 6 games to start as white. How do you decide which move to make? I seem to make a random opening for each game and see what happens. The game progresses from there.

I have tried to study openings before but have got bogged under the sheer amount to choose from. Has anyone got any tips or anything they found useful when studying chess openings? Any help gratefully received.