Why dose my skin get itchy, but mo spots?

Xerosis. The most common cause of itchy skin is xerosis. If you live in areas with low humidity, especially in the north where heat is used extensively, you may have a lot of xerosis (dry skin). Avoid the use of soap (especially dry brands), hot water, artificial fibers in clothes. Use plenty of thick moisterizer cream after bath. If that fails, time to see your doc.
Itch. This a challenging question to answer well in this forum. However, probably the most common reason why people may have itchy skin with no obvious rash is simply dry skin. Loss of moisture in the skin can cause itchiness. And during the winter months our typical means of heating our homes makes us warm but also tends to really dry out the skin. Beyond that you should see a dermatologist.