I’m interested in joining google. I’ll start working on it in august. Would be cool to get the job today.

Your expression isn’t really right, most of the time. It’s just heavy on the tongue. Try to make your short sentences easy to understand.

What do you do with “2017”, the best I can? What are I supposed to do?

If you need to include 2017 then

I will start working on Google on 20 Sep. 2017.