my hostings MySQL Disk Space is 37.57 MB. Is this enough for a 1500visitor/day blog? Do i need to increase mysql disk space?
That depends on how much data each visit creates. For some sites it would be enough for hundreds of thousands of visits/day, for some it wouldn't be enough for 100 visits/day.
I think if your blog doesn't save statistics like where users came from and such you have enough space, if the blog saves alot of info it would be gone sooon!
Depends on your usage. That said, ~40 MB of available space for a database is very little, expect troubles i.e. if you add few more articles to your site!