how can i reach hong kong airport from ramada hotel? can i check in at airport express station?

Hey, there are two Ramada in HK, one in HK Island, another in Kowloon, where are you?

If from the one in HK Island, you can take a taxi to HK Station and take airport express there to reach the airport.
If from Kowloon, you can walk to the northwest to Regal Kowloon Hotel and take free shuttle K3 to Kowloon station to take airport express there.

You can check in at airport express station after getting into the station by scanning the AE card / Octopus card (with enough balance in it).