Jesus is speaking about the people as if they were animals whose masters have forced to carry too much weight on their backs. This is a metaphor for all the laws and rules the Jewish leaders expect the people to obey. AT: "who labor under all the laws the religious leaders place on you" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "meek" and "lowly in heart" mean basically the same thing. Jesus combines them to emphasize that he will be much kinder than the religious leaders. AT: "I am gentle and humble" or "I am very gentle" (See: [[rc://en/ta/man/translate/figs-doublet]])
Here "soul" refers to the entire person. AT: "you will find rest for yourselves" or "you will be able to rest" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
Both of these phrases mean the same thing. Jesus is emphasizing that it is easier to obey him than it is the Jewish law. AT: "For what I place on you, you will be able to carry because it is light" (See: [[rc://en/ta/man/translate/figs-parallelism]])