Are you fine riding on roads?
There is the Bellarine Rail Trail that you can hop onto in Drysdale, ride to the Portarlington Highway and then ride that direct until the school (Geelong High), turn right at the school (hook turn if necessary), left into Malop and then right at Swanston to get you down on to the Beach Road (left at the Beach Road) which curves around the bay and turns into the Esplanade, then left at Glenleith and onto Church.
Or you could do the Rail Trail from Drysdale all the way into South Geelong and then turn right and ride the streets (possibly coming off the Rail Trail near Swanston Street and riding that one all the way down to Beach Road, then left and following along Beach Road until turning left at Glenleith).
I'm not familiar with cycling in Geelong city itself (I have driven to Drysdale along the Portarlington Highway many a time), so I don't have experience in riding there and hope that maybe some of the above directions are suitable.
Bicycle Network Victoria's map and information about the Bellarine Rail Trail:http://www.bicyclenetwork.com.au/genera ... ing/42478/
and http://www.bicyclenetwork.com.au/genera ... ing/42409/