First notebook entry: Introducing myself

Since the study, I need to learn the English, becoz because I would like to make some friends to improve my the English skills for studying abroad in future. I I'm grew up in Shanghai, so my native language is Chinese I mastered Chinese because becoz of my brother is Japanese, so I also can speak some Japanese. For the leisure In my spare time, I usually like to listen to music, as well as, play the tennis and football. I hope and finally wish we can help each other (out). (Your original sentence sounds like "In my spare time I usually wish we can help each other" which doesn't make much sense.)

NOTES:

Go back and review use of the article "the". You use it way too much in an unnecessary manner. I suggest reading some articles in English to get used to seeing how "the" is and is not used.

Put a space after each punctuation mark.

Capitalize the letter "I".

"Becoz" is very informal, internet slang. Since you are still learning English and not yet at a level where you can save you have mastered it, I suggest you stay away from all internet slang. I notice that people who use internet slang the most, are the worst at basic spelling and pronunciation. Also, remember that this is how lazy people type. 
 

First notebook entry: Introducing myself

Since the study (Since I want to study abroad in the future), i (capitalize, make it look like this --> I) need to learn the (not necessary to say "the English" since English is a proper name, for example you wouldn't say "the Pantene" or "the Jacob") English, becoz (because) i (capitalize the "I" when it's by itself) would like to make some friends to improve the (put "my" here because you are talking about your English skills) English skills for (to) study abroad in future (not necessary to put this since you have it in the beginning of the sentence). I'm (I'm means "I am", saying I am grew up is incorrect, say "I grew up") grew up in shanghai (capitalize this because it's a proper name, the name of a city), so i (capitalize) (add "have" after I, since "I" is a pronoun it needs a verb after it) master (make "master" into past tense because you already know Chinese) Chinese , becoz (because, when you see people write becuz or becoz or bcuz, that is internet/writing slang and is very incorrect when formally writing. My advice is to stay away from these kind of spelled words until you know English fluently. It even messes up native English speakers on spelling. It is used when people are too lazy to type out the whole word, so they take out letters to make it shorter) of my brother is Japanese so i also can (switch these "can also") speak some Japanese. For the (my, since it's your time that you spend doing these things you need to say "my") leisure time,I usually like to listen (add the word "to" after listen, it shows what you listen to) music, play the (not necessary to say "the" when it is a general term, "the" is used in referring to something specific) tennis and football, and finally (You hoping we can help each other isn't part of what you do to have fun, so end the sentence and start another one saying you wish we can help each other). (add "I" here because without it, the sentence becomes an order, like WISH we can help each other or else! You can to say "I" when referring to 1st person with the verb) wish we can help each other.

Since I want to study abroad in the future, I need to learn English, because I would like to make some friends to improve my English skills. I grew up in Shanghai, so I have mastered Chinese. Because my brother is Japanese, I can also speak some Japanese. For my leisure time, I usually like to listen to music, play tennis and football. I wish we can help each other.

*I hope this helps, and I do hope we can help each other! :D)