I once said in former posts that our families werused to be very poor before, so I didn’t have any toys thenas a child.

"Were very poor before" wouldn't sound completely wrong, but I wouldn't expect it in writing as much without a reference to a specific before/after event.

"Then" to me suggests that you do now, but that would mostly only make sure if you are still a child (even if adults can have toys).

But it didn’t representoesn't mean that I was bored during my childhood.

FouWe would find a branch-it, which was very easy to get, and meanwhile, others would grab a handful of soil and group it into small balls.

It sounds like you're trying to give a list of instructions, but those are generally written with the imperative (which is like the present tense form) or a combination of the present and future tense. Tenses that indicate the past aren't used.

"Meanwhile" suggests it happens at the same time, so that's why I wrote "others." If you want to keep "we," you would have to remove "meanwhile."

SWe would sticked the thin end of the branch into a small soil balball of soil and made sure the small ball was stuck tightly to the branch.

Also that the imperfect of "stick" is "stuck," not "sticked."
"Soil ball" is fine, but "ball of soil" sounds better to me here.

The game started:would start: we would shake the branch forward hard, throw the mud balls out, and see who throwsew the farthest.

The one who threw the farthest wasould be the winner.

The original is grammatical, but I'm using "would be" so that it's consistent with the sentences before.

This is a popular game that we played the most as countryside children.