Intruduce my self Introducing myself

Hello strangers!
I'm going to write about my self!  myself.
Firstly I'm from Korea and I'm 21 years old.
And I work in an elementary school.  teaching the handicapped/with the handicapped.
I educate for handicapped.
It's much too very (?) dificult difficult to care of for them but I'm worth to do.  it's worth it (?)
Sometimes they hit or scatch scratch me.
Even the one usually spit saliva on me! One even spits at me!
It spend takes a lot of time to understand them.
But I know they love me and I love them:)
They make me cry and laught.

And a About my hobbies,
I love to ride a bike.  bike riding/riding my bike.
I go to work by bike and in on the weekends I go for a ride by a the lake!
When Iit's hardly raining or snowing,
I had have no choice but I to get on the bus.
But if it is only drizzling, I'd rather ride a my bike.
Also, I love to swim.
I go swimming 3 times in a week.
I've been learning swimming for 3 months.
These days At the moment I am learning a breast stroke.
It's very difficult in comparison with the freestyle or backstroke.
But I think Iit is funnest the most fun!

Lastly, I'm interested in learning eEnglish.
I've been learning eEnglish since January.
I really hope to speak eEnglish very well~!
So so I study english it everyday every day. 
Will you You will help me, won't you!? :D

So Iit's time to say goodbye!
Thanks to read for reading and plz please correct me!
See you again~~ !

Well done!  It's hard to believe you've only been learning English since January - I'm sure you will be fluent in no time!  Your meaning is very clear throughout.  I've changed a few small grammatical errors.

Some notes:

* When you say where you work, I'm not sure if you are a teacher or if you just work in the school, eg, as an aide (helper). If you are a teacher, then you could say "I work in an elementary school teaching the handicapped" or if you are an aide, "I work in an elementary school with the handicapped".

* In the next line, when you say "It's much too difficult", that sounds like it's impossible to work there - I think you mean "It's very difficult..."  And I think you mean "it's worth it" rather than "I am worth it".

* Saying "I go for a ride by a lake" is 100% correct but it sounds a little more natural to say "the lake".

* Finally don't forget that English needs a capital E.

Intruduce myself

Hello strangers
I'm going to write about my self!
First I'm from Korea and 21 years old.
And I work in an elementary school.
I educate the handicapped.
It's much too dificult to care of them but it's worth it. I'm worth to do.
Sometimes they hit or scatch me.
Even the one that usually spits saliva on me!
It spend takes a lot of time to understand them. (note: Spend time is like hang out/ recreational. Take time is like to make the effort/ to use time)
But I know they love me and I love them:)
They make me cry and laugh.

And about my hobbies,
I love to ride bike.
I go bike to work by bike and in on the weekends I go for a ride by a lake!
When It's hardly raining or snowing hard, (note: hardly is not the adverb of hard. hardly means very little)
I had have no choice but to get on the bus.
But if it is drizzling, I'd rather ride a bike.
Also, I love to swim.
I go swimming 3 times in a week.
I've been learning swimming for 3 months.
These days I learn am learning the breast stroke.
It's very difficult in comparison with the freestyle or backstroke.
But I think It is the most fun! funnest!

Last, I'm interested in learning english.
I've been learning english since January.
I really hope to speak english very well~!
So I study english everyday.
You will help me, won't you!? :D

So It's time to say goodbye!
Thanks for reading and plz correct me!
See you again~~

It sounds like you have a difficult job! I hope these corrections are useful to you. One thing I did not correct was capitalization. You only capitalize for proper nouns. "It" is not a proper noun and you don't want to capitalize it in the middle of a sentence. Very well done! :)