Question

how can I practice my oral english

Answer 1

Practice it through speech. Use a mirror, and speak.

Answer 2

Use some kind of video messenger (like skype or something like that) to talk to someone who's mother language is english.

Answer 3

Listen to English as much as you can and try to imitate and understand it completely. You can watch English news online, radio, etc.
In conjunction with this, every time you ask somebody a question anywhere, ask yourself the same question in your head and try to say or imagine saying your answer. Better yet, have somebody ask you questions frequently.

Answer 4

Read english books! Try to speak more in English? :)