Sour, tart taste

Fermentation was complete, no more bubbles coming through airlock. I racked to plastic bottles for a still cider. This is my firt batch. I made 6 gallons and used a dry ale yeast. Temps were betwween 68-74. The color is light, but it tasted sour and tart. Is this normal? Will it taste sweeter in time? I did not add any extra sugar to it during fermentation. Wanted to see how strong it would be and taste without it.

Should i pour it all back into my primary and add sugar, or more juice? Or just wait? Thank you in advance for your help.

I'd leave it to age. Sour/Tart tastes definately mellow out with time, and when they go you'll find that you don't need extra sugar (like you feel you need now taste wise) to balance your brew. Be patient!