Answer: To some extent care will depend on what kind of jasmine you have as there are many different types. It is normal for faded blooms to drop off. I should mention that certain jasmines set their buds in winter then bloom in the spring, and do not bloom again until the following year so whether or not it should still be blooming depends again on what kind you have.
New plants do go through an adjustment period but should not defoliate to a noticeable amount. Defopiating is often related to over or underwatering, or a pest problem.
Jasmines usually do well in very bright but indirect light. The soil should be kept slightly moist, never saturated or sopping wet and not dried out. This plant also appreciates a high humidity level along with good air circulation. Very often dropping foliage is an indication of stress and/or overwatering, or possibly sudden exposure to excess cold. (Did it get chilled at some point?)
It might also be an insect problem such as spider mite -- suspect this if you also see fine webbing on the stems or along the dying foliage. These can be treated with commercially formulated insecticidal soap per the label directions.
Since this is a new plant you might also want to consult with your retailer. I hope this helps.
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