Hi BegumSu -
Wikia is actually a great place, more than just (but still including) blogs.
Blogs are about sharing things related to Wikia or your interests regarding such. The best place to go if you need help is, of course, the help pages - in this case Help:Blogs might assist you.
There are other special pages that can help you along your Wikia journey, such as:
More pages like these exist everywhere on Wikia. Here is a place to make friends and contribute in group efforts.
Good luck, happy editing!
Welcome to wikia, if you want to make a good blog just remember to write what you are interested in and make it the best you can be.
Good luck.