I am not sure if online check in is available to my itinerary...
Online check in is available on My Trip+ 24 hours prior to departure. 'Online Check-In' icon appears under the Flight Information tab if the airline provides online check in services. If the icon does not appear on the screen, that means the airlines does not support online check in.
I was forwarded to the English page after clicking on 'Online Check-In' icon...
By clicking on 'Online Check-In' icon, you will be linked to the appropriate airline's website prompting you to take necessary check in procedures. Some airlines may only provide you page in English.
"Terminal [W]" <-- What is an alphabet or a number displayed inside the brlacket for?
It indicates terminal information of each airport provided by OAG (UBM Aviation Worldwide Limited).