(one's) start
The beginning point of or first opportunity in one's career. Often followed by "in (something)." I got my start in publishing as an editorial assistant, and I just kept climbing the ranks from there. My father's friend was a senator when I was in college, she gave me my start in politics.
*one's start
one's first career opportunity. (*Typically: get ~; have ~; give one ~.) I had my start in painting when I was thirty. She helped me get my start by recommending me to the manager.