Day 1 : Willing to learn proper English

It's my first day joined here. (It's my first day on this website.)
Currently(,) I'm staying in Australia (with a)working holiday visa. I lived in Perth(WA) (a) few months ago(omitted comma) and I met some nice people who were very supportive to improve my English(awkward ending. Depending on what your trying to say, maybe try "supportive about me improving my English" or maybe "helped me improve my English"). But I had to go back to my country because of a dental problem. After getting the treatment, I moved to another city on the East coast to get a job. I feel (omitted) my level of English is getting worse than it was a few months before, so that's why I joined here(omitted). I'm looking forward to seeing some nice people who are willing to learn each other's languages and I'm ready to help. Thank you for reading these clumsy words. I'll happily listen to your corrections. Nighty night (Nice!) :)

So, I chose purple for correcting because red is too typical and blue is really hard to see on here. Anyways, this is really good. Yeah, there are grammar issues, but this is at a really good level. The most important thing is that I could still understand what you were trying to say. And that is the most important part. Your doing really well, keep it up!

Day 1 : Willing to learn fluent English

("proper" it is not correct grammatically, it use in informal conversations)

It's my first day here on Italki.
Currently I'm staying in Australia with working holiday visa. I lived in Perth(WA) few months ago, and I met some nice people, who were very supportive to improve my English. But I had to go back to my country because of my ( not caused by, you can also use "due to") dental problem, after getting the treatment I've moved to another city placed on the East coast for getting a job. I felt that my level of English is getting lower than few months before, that's why I joined here now. I'm looking forward to seeing some nice people who have willing to learn each other's languages, I'm ready to help. Thank you for reading this "clumsy" words, happily listen to your correction. Nighty night :)

My comment:

Very well structure but you just need to link the sentences better. Overall is good 7/10 ^_^