Set your sights on something/on doing something
Definition 1 of 1
Pro Tip 1/3Goal-Oriented
The phrase is often used to show determination toward achieving specific targets or ambitions. 
After finishing college, Mark set his sights on becoming a successful lawyer.
Pro Tip 2/3Personal Aspirations
Use it to talk about personal goals rather than shared ones or those imposed by others. 
Ever since she was a child, she had set her sights on becoming an astronaut.
Pro Tip 3/3Long-term Focus
The phrase suggests a long-standing aim, not a sudden or short-term desire. 
He has set his sights on learning three languages over the next five years.