Complex sentence: Earhart had her first lessons, beginning on January 3,1921, at Kinner Field near Long Beach, but to reach the airfield Earhart took a bus to the end of the line, then walked four miles (6 km).
Split into simpler sentences: Earhart had her first lessons, beginning on January 3,1921, at Kinner Field, near Long Beach. In order to reach the airfield, Earhart had to take a bus to the end of the line, then walk four miles (6 km).