unmanned JR station

noted some stations like Nakafurano station in Hokkaido are marked 無人駅. i suppose this is an unmanned station?

how do i get tickets from this station to board the train? is there ticket machine or do i pay for tickets in the train to the "train conductor"?

noted some stations like Nakafurano station in Hokkaido are marked 無人駅. i suppose this is an unmanned station?

Yes.

how do i get tickets from this station to board the train? is there ticket machine or do i pay for tickets in the train to the "train conductor"?

There is no vending machine at Nakafurano Station. Instead, you should take a numbered ticket from the ticket dispenser when entering the train. If you exit the train at another unmanned station, you will have to pay the driver when exiting the train or pay at the ticket gate of a manned station. If the train has a conductor, such as the Norokko, you can buy the ticket from the conductor. If you want to make seat reservations for the Norokko, you have to do so at a different station.

Some stations may not have anything but a little waiting hut like along the Kushiro marsh observation points. Those lines may run a one man car(driver only)train & no conductor. They may have the "seiriken" station no. ticket dispenser next to the driver like when you board a bus to identify which station you boarded. You pay to the train driver when you get off. There are some lines like that in Kyushu & other remote places, too.

thanks, i will take ticket number from driver when boarding at unmanned stations.

Not from the driver. From a small box next to the door. It works similar as in local buses, which are explained here:
http://www.japan-guide.com/e/e2015.html

thanks, i will take the ticket from the box near the driver. if i enter from other door, then i will have to walk to the first car where the driver is? or is there ticket box on every car?

It depends on the train (sometimes the box is near the front of the car, sometimes it is at the back of the car), and I am not familiar with the particular one along the Furano Line.

Also, sometimes the train is just a single car, sometimes it has multiple cars.

I recommend to relax, follow the other passengers, look for the box with numbered tickets and not too worry too much.