Hmm. Not bad. If I may, there are a couple of corrections that I would like to make. I will use Romaji, but I will put spaces between the hiragana names for ease of re-entry. Now, the first correction is one of those times where the phonetics aren't as obvious as I would like, but it does make some sense. Hello = konnichiha ko n ni chi ha
The wierd part is that last character. Ha is traditionally used, as this word used  to be more commonly  part of a sentence. Thus, the ha at the end is not in fact part of the word, but the particle ha which is pronounced wa.
Your counting is good. go=5
8 = hachi ha chi
9 = kyuu (and here's where my laziness comes to bite me, as that is ki followed by a small yu I think. Any more qualified speaker can correct me on that one, though.)
10 = Jyuu (same concept)
And with that, I have tought 1 through 99 because...
11 = jyuuichi
12 = jyuuni
...
20 = nijyuu
30 = sanjyuu
...
It would go number, followed by the place the number is in, in this case, the tens place, followed by the number in the ones place.
Anyways, I hope this all made sense. Sorry for the lazy method of doing things, and as  usual, I haven't practiced in a while, so sorry if I got anything wrong.

oo nice!
I am using duolingo

I think that's his signature. Still not wrong, it's more like he hasn't updated it, though, rather than getting it wrong again. I also wanted to write in a way to demonstrate that little quirk. As, that particle is commonly used, and this is an example that both shows its use being ha but being pronounced wa, and it gave me an excuse to talk about the particle a bit. It really is kind of an oddity to me. Much like wo being pronounced o, though that one is less strange.

I can't understand anything, just japanies letter

Not an oddity really though, just an evolution of the language.The ha pronunciation is common for older people, because that is how it used to be pronounced. Not sure when that pronunciation fell out of use, though. Wo and o is the same thing. Older pronunciation vs. newer.

The ha and wa stuff isn't too terribly important. It  really is more theory for now. Once you start learning how sentences are constructed in Japanese, you'll understand the bulk of it. I should really get me a japanese signature. LOL!!!

No problem. Best of luck on your language learning adventures. Japanese is a fun language. I enjoyed those classes I took, I hope you enjoy your studies as well.