The words "we" and "us" refer to the author and his readers. The word "you" is plural and here refers to the readers. (See: [[rc://en/ta/man/translate/figs-inclusive]] and [[rc://en/ta/man/translate/figs-you]])
The writer speaks about the Old Testament believers as if they were a cloud that surrounded the present-day believers. This can be stated in active form. Alternate translation: "such a large cloud of witnesses surrounds us" or "there are so many examples of faithful people about whom we learn in the scriptures" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])
Here "weight" and "easily entangling sin" are spoken of as if a person could take them off himself and put them down. (See: [[rc://en/ta/man/translate/figs-metaphor]])
Attitudes or habits that keep believers from trusting and obeying God are spoken of as if they were loads that would make it difficult for a person to carry while running. (See: [[rc://en/ta/man/translate/figs-metaphor]])
Sin is spoken of as if it were a net or something else that can trip people up and make them fall. Alternate translation: "sin that makes obeying God difficult" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Following Jesus is spoken of as if it were running a race. Alternate translation: "Let us continue obeying what God has commanded us, just like a runner keeps going until the race is over" (See: [[rc://en/ta/man/translate/figs-metaphor]])