how much is cost to take train to and back?
do there have any cafe to have lunch?
>>how much is cost to take train to and back?<< It depends where you start from.
>>do there have any cafe to have lunch?<< Who are they ? Do you feel they are after you ?
I will assume you mean the train which runs along the jetty. There is no train to Busselton.
Since you're on the internet, I'm surprised you didn't look for the Busselton Jetty's webpage, which has all the information you seek:
When we were there some time ago they had a second section which did cheaper take away style food but I don't know if it's still there.