I looked at its leaves and ther wer little insects on with shells is it fine if i spray it wilth oil
Best thing is to first identify the insects and then take the right approach to get rid of 'm.
Did you actually read the care guidelines? The first section tells you where it should be:
"Position: Place the tree outside, year-round, on a bright spot with lots of sunlight. The Juniper cannot live indoors. "
