Hello, my suggestions and edits are below:)
Make this your first paragraph...
Education and a great life are crucial things for human beings. Getting excellent grade(s) in( your) school or university is one of the (many) ways to achieve ( a) bright future. I personally argue that intelligent people without making efforts with ( of) studying hard are impossible to reach high quality of life. ( Great first paragraph would love to see more in a couple of sentences elaboration here)
In today's world, having good education is an essential element for a better future. It is a key to attain the millennium development goals (.)Firstly First and foremost, it ( what is it?, school?) is predicted to make (help )students gain well-paid and respectable careers with a good education. For instance, American employers in general will be (are) impressed with an applicant who has studied overseas as it shows that they have international experiences, which is highly valued in ever more globalized society ( great sentence showing a statistic makes argument strong) .
Make this your second paragraph...
Secondly (Second), it ( education) prepares students' mind to make sane, healthy (,) and intelligent decisions about any situations that one may encounter in life's journey. As result, Great education is a worthwhile investment from human beings. (It would be helpful here to argue how these intelligent decisions prepare you, add a couple more sentences).
Studying hard is related to the better life. For this reason, it is estimated to be a best gate in achieving the study purpose. Taking one example, In in term cram schools is in Japan, currently known as "juku". Juku are special private schools that offer lessons conducted after regular school hours and on the weekends. Students who (are) sent by their parents can study to improve test scores and to get (a) good grade in their schools. In addition, it helps pupils to prepare for university entrance examination. Tip: You can add this part to the second paragraph but you must tie this is with how Education is a worthwhile investment. If not it has to be a stand alone paragraph
Ultimately, great education is the most important possession that people must have. It is beneficial in many aspects of lives. Therefore, in my view, the most important factor for students to achieve the best future life is studying hard.
You have a great start here! You have great ideas but you need to organize your ideas. You are making a argument but your ideas are all tied together and jumbled. It may be easier for you to follow the exact prompt. Make each question of the prompt above a paragraph so that you stay on track, answering each question in a organized form,
Tip: Try to stray away from using the word "it", by replacing "it" with the actual noun.
Good luck and great job so far!