This paragraph is about leadership and political leader in particular.
國 means "country". However at Confucius time, 國 is more like an estate with a ruler, appointed by the emperor. 千 is "thousand". I wrote about the first ten digits in the last post. For you to be able to express number, you will need to learn these as well. 零,十,百,千,萬,億. 零 is zero. 十,百,千,萬,億 are units representing ten, hundred, thousand and ten thousand. Note that unlike western system where the number of places are grouped in three, in Chinese, the number of places are grouped in ten thousand. So 123,456,789 which is one hundred twenty three million four hundred fifty six thousand seven hundred eighty nine should be regrouped as 1,2345,6789 and expressed as 一億二千三百四十五萬六千七百八十九. I hope you get the idea.
千乘之國 is the largest estate. The Emperor's own is referred by the largest unit - 萬.
Nowadays, 道 has five different meanings: nature's law as is 天道, or 道理; moral as in 道德; the way as used in LaoZi's Tao Te Ching; path as in "road" and finally as an alternate for "say". The last meaning attached to 道 much later than Confucius. So 道 here means "the way". Confucius was talking about how to govern, be a good leader. He listed three important points.
敬事而信, respect the job and establish trust.
Confucius was very aware that a leader could not be an expert in every area. When there is a job, do it with respect 敬事. When delegating a job, do it seriously. I have explained the character 信 means trust. So when a leader delegate a job, the leader has to trust that the person has the ability and integrity to carry out the job. When doing a job, do it with trust and integrity.
節用而愛人, save and love the people.
使民以時, when asking people to work for you, pick the right time.
Putting it together
Confucius said, "To be a good leader, respect the work and establish trust, save and love the people, timing is everything."