We went to ride bicycles.

You can also say, "We went bicycle riding" or "We went on a bicycle ride"

Last time, we went there it was quite good.

Sunshine was nice and we ate bread we had prepared.

You can also say "the" sunshine was nice.

But today, it wasn't like that.

You should add something after "wasn't". For example: it wasn't good, it wasn't so nice, it wasn't like last time, etc.

There were huge trucks being around.

I think it would sound good to say "There were huge trucks all over".

"All over"/"all over the place" = everywhere.

"Around" is also okay :) (or "all around", "around the place").

The water iwas smelly.

Dead fishes were floating around the edge of the water.

It reminded me of the fact my friend told me that the water was very dirty because of the livestock facilities.

The waste water would had beenas flowing out from some of the facillities without being disposed properly.

1. was flowing = You know the waste water was flowing out.
2. might have been flowing, could have been flowing, was probably flowing, was possibly flowing, etc. = You are guessing that the waste water might be flowing out.

I don't know whether they had been punished.

"whether" is like saying "if".

"Farmers will do rice farmingfarm rice using this water.

Anyway riding a bicycle reduced my guilt fover not to exerciseing and made me feel better.

Often we use the word "over" with "guilt".

Guilt over X = guilt about X, guilt due to X, guilt because of X, etc.

At home, we ate an orange that we were planning for snacks at the reservoir.

You can also say "an orange that we were planning on snacking on at the reservoir."

to snack on = to eat something as a snack

Last time, we went there, it was quite good.

Sunshine was nice and we ate bread preparedthat was prepared ahead of time.

We could see the birds that were not seen easily seen.

There were huge trucks being around.

Dead fishes were floating around the edge of the water.

Fish doesn't have to be plural here. Either way works.

It reminded me of the fact that my friend told me that the water was very dirty because of the livestock facilities.

The waste water would had beenhas flowed out ofrom some of the facillities without being disposed properly.

I doidn't know they had been punished.

We turned around and came back to home.

I don't like the wind in this season.

I love the sunshine of Sspring but hate the wind.

Anyway, riding a bicycle reduced my guilt for not to exerciseing and made me feel better.

"I realize we live in thea rural area when we ride bicycles."

At home, we ate an orange that we werehad planning fored as a snacks at the reservoir.