Project window has LINKS to footage items, not footage items itself -- similar to Premiere.
Types of files that can be imported include:
Video & Animation: Animated GIF, MOV, AVI, FLM (Photoshop filmstrip), SWF, WMA, WMV, Photoshop images with video layer
still-image files: JPEG, PSD (including layers), PDF (first page); Bitmap, Camera Raw, EPS, Maya, PNG, TIFF
audio files: AIF, AIFF, MP3, WAV, AVI
other After Effects projects (AEP)
Premiere Pro projects (PPJ files)
Start a new project
File>New>New Project
Save project and continue to save it as you build it, in case program hangs up.
File>Save saves file with name you enter (first time) or current name once project has one..
File > Increment And Save saves a copy of the project with a new automatically generated name
which is the original name followed by a number.
File > Save As saves the project with a different name or to a different location; the original file remains unchanged.
File > Save A Copy saves a copy of the project with a different name or to a different location. The open project retains its original name and location, and a copy is created with the new settings but is not opened.
Edit > Preferences > Auto-Save and select Automatically Save Projects to automatically save copies of projects at regular intervals,
Importing files
Different ways to import files into project
Open them from within Adobe Bridge
File>Import and choose Import single file or Import multiple files
Filie>Browse opens Adobe Bridge
Drag files into After Effects Project panel from Bridge
Imported file names are listed in Project window
Can reuse one file multiple times in project & keep original file name only once in project window
If you delete, rename, or move an imported source file, the reference link to that file is broken.
When link is broken:
the name of the source file appears in italics in the Project panel,
File Path column lists it as missing.
If the footage item is available, reestablish the link by double-clicking the item and selecting the file again.