By default there is a blue centring mark at the top-left junction of the rulers. You can drag this to any point on your drawing to reset the ruler zeros to that point.
I’ve not had this issue. In the Print… dialogue have you got the ‘Pages - All’ radio button selected and 'Pages per sheet set to 1? Also in the ‘Layout > Drawing Size …’ dialogue have you set the 'Pages in Drawing to something appropriate (probably 2 and 2)?