My 96 countour trans problems?

my contour when i start it and put it in drive it wont upshift at all so i put it in 1rst then manually in second then manually in third it then upshifts and down ships through the lenght of the trip but if i just put it in drive it wont .....as well the speedo isnt working whats goin on is it the speed sensor thats what the computer said it was .what that solve the speedo not working problem or both the shifting problem and speedo problem please help ryan