Verses 6-12 repeat for a second time and give more detail about how Noah went into the ark with his family and the animals in Genesis 7:1-5. This is not a new event.
These were animals that God allowed people to eat and to give to him as sacrifices.
These were animals that God did not allow people to eat or to give to him as sacrifices.
two by two
The animals entered the boat in pairs of one male and one female.
It came about that
This phrase is used here to mark an important event in the story: the start of the flood. If your language has a way for doing this, you could consider using it here.
after the seven days
"after seven days" or "seven days later"
the waters of the flood came upon the earth
The implicit information, "it started to rain" can be made explicit. AT: "it started to rain and the waters of the flood came upon the earth" (See: rc://en/ta/man/translate/figs-explicit)