Are you free around 10 o'clock on Friday morning? I'm studying for the Proficiency Exam, so I'd like to speak a little in Japanese.
Remarks about the translation
The second sentence is in unnatural/mistaken Japanese, but the meaning seems to be: "I want practice my spoken Japanese with you at 10 am on Friday if you're free at that time, because I am studying for the Japanese language proficiency test (Nihongo Nôryoku Shiken)."