Hello eveyone

Hello everyone.
This is my first message for italki.
I think to want to be the person who can speak english more better.
Last week, I had found this site , italki when searching something on the Internet.
And I thought this site give me the opportunity to communicate with someone who can speak english and to improve my english.
Off course, I intend to help you to improve your japanse skill.
See you.

This is my first message on italki.

I think I want to a person who can speak English better.

I found italki last week while searching for something on the internet, and I thought that this site would give me the opportunity to communicate with someone who can speak English.

Of course, I intend to help you improve your Japanese skills.

See you.

Blue = my correction

This = not needed

Red = needs to be capitalized

Hello eveyone

Hello everyone.
This is my first message on for italki.
I think I to want to be able to the person who can speak eEnglish more better.
Last week, I had found this website called italki, while I was when searching for something on the Internet.
And I thought this website would give me the opportunity to communicate with someone who could can speak eEnglish and  help me to improve my eEnglish.
Off course, I intend to help you to improve your jJapanse as well skill.
See you.

As a side note, you should not start sentences with "and".

Hello eveyone

Hello everyone.
This is my first message for italki.
I think I want to be able to speak english [no need for 'more', 'better' = 'more good'] better.

[You could also say 'I think I want to be the kind of person who can speak English better', but that sounds awkward.]
Last week [no comma] I [had] found this site, italki, when searching for something on the Internet.
[And] I thought this site could give me the opportunity to communicate with someone who can speak English and [to] improve my English.
[Off] Of course, I intend to help you [to] improve your japanse skill.
See you.

:)