'He went down the aisle...' vs 'He walked down the aisle...'

[Twilit1988]

My dear and respected teachers,

1: "He went down the aisle with a rich lady." And "He walked down the aisle with a rich lady." Is it correct to say or I should remove "with a rich lady"?

2: "Let's get started." Why is 'get' used?

3: "Write the names of the days in a week." correct?

[Sajan]

The first 2 sentences look all right to me.
"Get" is sometimes used as a substitute for "be" (get+done) or "have" (get+smth+done) in passive voice (the full version of your sentence would be let's get it started).
I'd say "Write (down) the days of the week".