Look at as many other people's work as you can. Really look and then ask what you are drawn to, what fascinates you. You will be at the beginning of understanding the style and subjects that inspire you. Now set about unashamedly copying them. This will develop your skill in mastering the style and subject. From there it is a short step to developing your own original approach. Your search through other people's work will lead you to the subjects that inspire you and you will learn so much from them.
Another approach. Imagine you have a friend living in, say, rural Africa (or anywhere else for that matter). Now imagine how the region you live in would be fascinating and unusual to your friend. Look at it through his eyes. If he came to visit you, what would you show him and what would you tell him? Then set about creating a photo essay that would convey to your friend what is so fascinating, unique or unusual about the area where you live. Then make a photo book. Having a tangible goal like this will concentrate your mind and help motivate you.
I have found this is a powerful technique for seeing my area with new eyes.