What you want is more akin to a Cosmic Zoom effect – not a fly through which is closely associated with laying elements in 3D space and then flying a virtual through this space.
For the Cosmic Zoom, Andrew Kramer has a very good tutorial. You will find it on his https://www.videocopilot.net site.
HTH
RoRK
Intensive AE & Mocha Training in Singapore and Malaysia
Adobe ACE/ACI (version 7) & Imagineer Systems Inc Approved Mocha Trainer