I don't want to say or ask too much.. but any of you guys know how to edit vids and audio?

If any of you guys know could you help me with something..

1) Where and what should I get a free software which can edit the sound of the video? The safest and easiest ways..

2)How do you remove a video that has someone talking in it and you want to remove all the background vocals?

3) How is the fastest way to make a video?

4) Any ideas on a video..? It's for teacher's day.. [yeah, my school's just celebrating it since our exams were on teacher's day, so they moved it to tomorrow -.-"]

5) Pleaseeeeeeeeee~~~~~~~~~~~~~~

URGENT!! I need answers like right now... I don't care if I stay up all night doing this video, because it is special to me.. Thanks in advance.. ^^ + the panda eyes.... and still sick me.. [I'm still sick]