May I ask how you were even chosen since you know nothing about teaching? Or why you even accepted the job? No offense, but the whole thing sounds like a friend or co-worker thought you were a native English speaker and that that was enough to teach. Obviously incorrect.
Suggestions:
Start watching Friday morning TV (NHK) and copy stuff from Eigo de Asobo.
These kids' brains are empty of English yet full of openness; exploit that. What do you think a native speaker would be learning at that age? As mentioned above, things like colors, numbers, letters, small words (in writing), verbs with opposites (go vs. stop), adjectives with opposites (hot vs. cold), shapes, and simple commands. Simon says is a winner. "Go get me a..." is another one. Do lots of repeat after me stuff. Go to used bookstores for kids' English books. Make your own zoo animals, fruits, and vegetables.
I suppose you're expected to teach them together, too, eh? That's stupid if it's what is expected. Far too great a difference in age and level, so negotiate separate lessons for the 7-year-old, if nothing else.
what do i need to further explain to receive help? ☝We should have guessed you were still school-age yourself when we saw that you waited until the absolute last minute to seek help with your homework.
Seriously, though, all anybody knows about you and your situation is what you present. The onus is on you to do an adequate job of explaining the situation.
At this point just teach them vocabulary. Kids are sponges, whatever you throw at them will probably stick.
Colors, numbers, animal names. Teach the older one simple sentences like a self introduction (I am Taro. I am seven years old. I have two brothers. I like food. etc...). Songs are also good, but will probably require more preparation. Make it FUN for them. Learning English at this age (or any age, for that matter) should not be a chore.
Just make sure that they come away with some knowledge demonstratable to their parents, to show them that "hey, they actually got something out of that!"
That's easily enough answered by watching Eigo de Asobo on Fridays. The singer/songwriter/teacher Eric has wee little kiddies using as close to normal sounding English as their tongues can muster. You can't please everyone, though. My own kid is half Japanese, and at 3 still makes a lot of Japanese-English sounds simply because he isn't exposed to English 24/7.I'm wondering how posters with EFL experience would tackle the issue of pronunciation in this instance. When initially running through some simple vocabulary, should the kids be expected to say (eg) 'dog / cat' or 'doggu / kyatto' ?
If they haven't yet been 'educated' in katakana-based English at school, perhaps they might find more natural pronunciation easier... now's the chance to get 'em while they're young