Here are the sentences rewritten in passive voice:
The competition was won by me yesterday.
The dogs were walked by her five minutes ago.
Soup was made by us yesterday.
Some mushrooms were picked by them last autumn.
A glass was broken by him an hour ago.
The series was watched by me last night.
A dress was worn by her yesterday.
A mistake was found by me ten minutes ago.
Some sweets were bought by us last Wednesday.
A wallet was stolen by someone last night.
Beautiful socks were knit by my granny last winter.
Tasty jam was eaten by us last December.
Some money was lent by him last year.
Paris was visited by me last spring.