I am looking for a train leaving from Cambridge on Saturday.
Sure can you tell me where you are heding for and what time you would lie to leave or get there?
The train should leave after 16:00 and should depart from london liverpool street
I'm a little confused, you said you are departing from both Cambridge and London Liverpool street. Are you sure isn't your destination? 
Sorry, I'm departing from london liverpool street.
There are four trains on Saturday with that route that leave after 16:00. Your options are 17:39, 19:39, 21:39 and 23:39. The duration of the ride is 88 minutes.
Can I get the price on one of those please?
Each of those trips is 13.28 pounds.  Would you like for me to book one for you?  
No thank you. Please give me information on the attraction Jesus Green Outdoor Pool.
Yes its located between Victoria Road and the River