First time

The last sentence sounds weird. 

First time

You should be very proud of yourself! You're off to a great start! Keep up the good work!

First time ('First entry' sounds better, but there is nothing wrong with 'First time', grammtically)

Many people ask me about how long I have been learning do you learn English.
In Taiwan, we were learn English from junior high school.
But my English is also poor.
I want to learn better and can speak conversation more fluently.

Just a few minor errors, great work! Stay motivated and with a bit of practice, you ought to be fine =)

First time

Many people ask me, how long I have been learning do you learn English.
In Taiwan we are taught were learned English from junior high school, but my English is also still poor.
I want to learn more better and to be able to can speak conversation fluently.

First time

Many people ask me, "How long have you been learning English?"
In Taiwan, we were learn English starting from junior high school. But my English is also poor.

I want to learn better and speak fluently in conversations.

Good entry, William.