Your plant appears to be a Ficus benjamina, a member of the large fig family. If we’re correct, when a leaf is broken off, a milky latex will exude. Ficus like bright, indirect light, moist (but not soggy) soil, and a permanent location. When their pot is moved, they often respond by dropping all their leaves. Thankfully, these usually grow back.The container needs to be well draining and do not allow plant to sit in water as this may lead to root rot. In some climates the tree does well planted in the ground. From this photo we cannot tell for sure if this is a F. benjamina. If you disagree, please take a few clippings to a horticulturist at your local garden center to see if they can identify the plant and the problem for you in hand.