writing a speech (pinyin)

Hello,

I am currently writing a speech as an assessment of my Basic Spoken Chinese course.

I have searched through many dictionaries and phrase books, but can't figure out how to say (or even if it is grammatically possible to say):

"First, I would like to thank my teacher for teaching me to speak Chinese."

"because these were the only phrases I learnt, when I was shopping in China" 

and

"He will be 18 years old on the 11th of September."

I think I'm getting stuck on how to express the present/past/future tenses. We haven't really gone into them. 

Any suggestions/recommendations would be great!!

-penelope