First of all, I would like to thank you all for always correcting me.

More natural!

This assignment is due in two months but I wish complete it earlier so that I'll have more free time in the future.

the future is implied !

Think about things in your life that you would like to improve in your lifeon.

Or:
Think about things that you would like to improve on in your life.

I want to finish my book "a ma book summary I am writing, on a book called "A Mind for nNumbers"

I am going to assume it is a book you are writing. Titles of anything streets, names, companies, books need capitals always !

I want to organize my time more efficiently my time.

or: I want to spend my time more efficiently.

I want to be more kind with more people, and to smile more often.

I want to have friends from other countries such as Japanese, Chinesea and the United States people.

No need to say people, friends is implied as humans already!

I want to sew more clothes toso that I can become a professional fashion designer.

Or: I want to make more clothes so that I can be a professional designer.

I want to watch internet courses related to fashion design in order to improve my sewing skillskills in sewing.

More natural, the tone is more imperative and emphasises the purpose of the internet courses ! (With the in order to)

I want to read the book "The Cashflow Quadrant" so that I can stop trading time for money and start creating systems that works for me instead of me working for systems.

I want to improve my skills I already have such as sewing and my speaking languages soproficiency in the languages I have been learning so that I can get a better job.

I will be a polyglot; thatis will allows me to have friends from other countries and to have better access to more information.

I will master English and Japanese and I will have started learning a new language.

I will be efficient, and be able to organize and prioritize important goals such as my studies and workmy job.

I will be more kind and friendly (to others).

I will improve my sewing, dancing, and painting skills.

I will read several books; therefore and thus I will have morean extended vocabulary.

Or: I will have a broader vocabulary.

This assignment is due in two months but I wish to complete it earlier so I'll have more free time in the future.

In this assignment I need to write things I would like to improve about myself,: emotionally, professionally, and economically.

A colon is used to introduce a list of things.

I want to finish my book "a mA Mind for nNumbers"

Use capital letters for names of things

I want to organize efficiently my timemanage my time more effectively.

Sounds more natural.

-InNext year/over the next year.

EmotiPersonal (family and friends).

I want to be more kinder with people, and smile more.

-InNext year/over the next year.

I want to take care of my grandmother so she canwill live longer.

I want to have friends from other countries such as Japanese, Chinese and United States people.¶

I want to have friends from other countries, such as Japan, China, and the United States.
Or
I want to have Japanese, Chinese, and American friends.

I want to sew more clothes to help me become a professional fashion designer.

I think this sounds better

-InNext year/Over the next year.

I want to watch interonlinet courses related to fashion design to improve my sewing skills.

We tend to call them online courses instead.

I want to read the book "The Cashflow Quadrant" so I can stop trading time for money, and start creating systems that works for me instead of me working for systhems.

Stope repetition.

-InOver the next year./next year

I want to improve my skills, such as sewing and speaking languages, so I can get a better job.

I will be a polyglot; that will allows me to have friends from other countries and access tomore information.¶
Or:¶
and to access more information.

I will improve my sewing, dancing, and painting skills.

I will read several books; therefore I will have morea bigger/wider vocabulary.

This assignment is due in two months but I wishould like to complete it earlier so I'll have more free time in the futurelater.

In this assignment I need to write things I would like to improve about myself, emotionally, professionally and economicfinancially.

I want to finish my book "a mA Mind for nNumbers."

I want to organize my time efficiently my time.

I want to improve my Japanese, and be able to speak more fluently.

-In the next year.:

I want to master English.

-In two years.:

I want to be more kind with people, and smile more.

-In the next year.:

-In two years.:

I want to have friends from other countries such as Japanese, Chinesea and the United States people.

I want to sew more clothes in order to become a professional fashion designer.

-In the next year.:

-In two years.:

I want to read the book "The Cashflow Quadrant" so I can stop trading time for money and start creating systems that works for me instead of me working for systems.

-In the next year.:

-In two years.:

I will be taller, and my hair will be longer.

I will be a polyglot; that will allows me to have friends from other countries and access to more information.

I will be efficient, and be able to organize and prioritize important goals such as studiesy and work.

I will improve my sewing, dancing, and painting skills.

I will be healthier,; I will eat the nutrients that my body needs.