Task: I had to go to Berlin for an important work, so I used the Trainline app to look for a Train from Southampton to London Blackfrairs on October 31 
Steps:
Open Trainline app
Click on the departure station
Type southampton in the origin tab
Click on the southampton any
Type London Blackfrairs in the destination tab
Click on the London Blackfrairs
Click on the Find times and prices
Click on the Find times and prices