I like to make a micro wind power, can I use a small DC toy motor and attach a small plastic propeller ? If not then what's can I use ?
It can be done.
A demo I have seen had a propeller about 6 inches across. I have no idea how much wind is required to get any output.
Here is something on line. I expect there are others if you do an google search…
http://www.amazon.co.uk/Kidzlabs-Green-Science-Windmill-Generator/dp/B000W2I91I