I created a new composition and dragged in my video which has a length of about 4 minutes. But my composition window does not show the whole timeline of the video just until 30 seconds and then I have to drag the line in left direction just to work with the rest of the video but there is one problem: the effect lines just stay where they were before. How can I make the window show me the whole timeline?
Seriously: Read the help!!!!!! These are basics. Composition --> Composition Settings. Magic!
I am a little confused as to what you are trying to explain here. Can you see your whole video, but only if you scrub the "Zoom In" tab around, or do you have to pull the actual video layer around to see whats happening?
If I am wrong in this assumption, please forgive me, but are you quite new to AE? If thats the case, for now, it might be a better idea to rather right click on the imported video and select "New comp from selection" - that way, the comp will be the correct length, and "Type" for your footage. Each AE comp can be custom created to allow for a large variety of different needs.
Send a screenshot if you like, so we can maybe point out some more detail, but I think you will need to spend some time here: