Introduce myself!

Hello there! Let me introduce myself. (You do not need to say this because you are already introducing yourself) You can call me 'A'. I'm a teacher.I teach in Thai Language Subject which is about literatures and grammars. (This will make the sentense shorter and easier to say. You do not need to say what it is about if you just tell us what it is). If you wanna know about them learn (the word learn is simpler and it means the same thing) you can ask mean me right now.I'll reply you all questions.Nice to see you all in on here. (do not put the period here because the sentense is not over if you put "<em>and</em>") :) and See see you next time...

This is how it should look with the corrections:

Introduce myself!
Hello there! You can call me 'A'. I'm a teacher. I teach Thai literature and grammar. If you wanna learn you can ask me right now.I'll reply you all questions. Nice to see you all on here :) and see you next time...

Hello there! Let me introduce myself. You can call me 'A'. I'm a teacher. I teach in Thai Language Subject which is about literatures literature and grammars grammar. If you wanna know about them Thai Language you can ask mean me right now. I'll reply you to all your questions. Nice to see meet you all in here. :) and See you next time...

Introduce myself!
Hello there! You can call me 'A'. I'm a teacher. I teach Thai literature and grammar. If you wanna learn you can ask me right now.I'll reply you all questions. Nice to see you all  and see you next time...

Introducing Myself!

Hello there! Let me introduce myself. You can call me 'A'. I'm a teacher, I teach Literture and Grammar in Thai Language Subject which is about literatures and grammars.If you would like to wanna know learn about them you can ask mean right now. I'll reply to all your all questions. Nice to see you all in here. :) and See you next time...

Introduce myself!

Hello guys,Let I  introduce myself.You can call me 'A'. I'm a teacher.I teach Thai Language  which is about literatures and grammars.If you wanna learn about, you can ask me right now.I'll guide  you all about thai,. See you next time...