They are two very different things.
Confucianism is an ancient philosophy born 2500 years ago. Its basic doctrines are about love, loyalty, discipline, and etc. It spread ed to Japan, Korea, and S.E. Asia nearly 1500 years ago. That's why the Japanese and the Chinese seldom smile

). You may find it to be similar to the tracings of Jesus and Plato.
Communism was born in Europe nearly 100 years ago. It spread ed to Russia, China, Vietnam, Cuba, and etc after the two world wars in the 20Th century.
In short, Confucianism is a religion, a way of life. Communism is a political doctrine about the economic and political systems.It died 25 years ago. In comparison, Confucianism is alive in East Asia and S.E.Asia even today, just like Christianity still alive in Europe even today.