Peachey is right, NEVER use "wanna".
Peachey's comments are also good. I'd add just a little on the second paragraph about "blunt" & "rude".
Each employer has their own culture.
For some places, employment is a negotiation, you offer services & they offer compensation. Others are different. Some say the place you work should match what you want.
Sometimes, you need to tell them what you plan to do. Similar to "I'm looking forward to..."
From your point of view what do you want to achieve?
"For myself, I'm looking forward to the challenge of .... " personal growth ambition...
"I think I can contribute to this company...."
In some places people ask things like, "Where do you want to be in 5 years?". Have some ideas ready.
"In 5 years time, I'd like to be contributing ...." how?