I need tips for teaching three 9-10 year-old children English.THX

You might consider some captioned children's stories that can be found on YouTube or in e-book format. That way, they'll read the words, hear the pronunciation, and associate the images they see with words in both languages.

For the video below, you could create a treasure hunt that has them making a list of all the words that rhyme in the story.

Here's an example of one:

Great, But I have problems accessing YouTube , SO, I will try to find another story ,create a different Scenario.

THANK YOU.

Always speak English:
There will be words they might not understand. Explain them in English or with "behavior", which will with time make you into a wonderful actor.
Explain DOG, that is easy - you bark. Bird flap your arms.
There will be many funny situations doing this.
You can also make the children to act a thing/animal/person/verb and the others have to guess.

yes yes,
we did that last year,
like when Iwere teaching "painter dancer reader singer "etc.
yesterday I asked them "what do you want to be in the future?"
they can answer the question,"I want to a painter "etc.

and the boy asked me how to express the owner of a shop, I told him it's call a boss, and he answered "I want to be a boss in the future".

Actually, an owner of a shop is called a proprietor.

A boss doesn't neccesarily mean that this person is an owner. An owner may hire another person to run the shop.

haha,
I did give it a second thought there, but I think the word "boss" is much easier to remember, for the boy.

hope it's not a huge mistake.

Well, the point is that it's not accurate.

You can also call that person a shopkeeper.

yeah I got that.