What do you usually play with your friends?

I usually play computer games with my friends. ✔

​

What does the engineer do? --> What does an engineer usually do? 

​ Engineers usually design bridges. --> An engineer usually designs bridges. 

Wow! Great!  I want to be an engineer --> Wow, wonderful! I want to an engineer. 

=> Your sentence has a correct grammatical structure, but this has the correct usage/ expression.