: Sites like ProDesignTools traditionally hosted direct download links for legacy versions, though they report that Adobe has recently pulled many of these older files from their servers.
If you already have the software and need a guide to using it: New Adobe After Effects CC 2018 features Adobe After Effects CC 2018 Download Free
However, you can still access After Effects for free via a trial of the current version or explore alternative ways to find older installers. Official Free Trial (Current Version) Adobe After Effects CC 2018 Download Free