Today, I took on part-time job for five hours a day (a week?). Each time reminds me just how hard it is to work. Working is really hard but I strive with an aim in mind: to go abroad for study. I’ll keep working so that someday I can converse in English with people around the world. I’d like to make the effort to achieve my dream through work.

Today, I took on a part-time job for five hours [five hours per...? day? week? in total?]. I realize again each time how hard it is to work. Working is really hard, but I am striving to achieve a goal, which is that I would like to study abroad. I’ll keep working so that I can talk in English with a lot of people from around the world. I’d like to make efforts to achieve my dream through work. [<-- This last sentence isn't wrong, but it sounds odd. Perhaps, "I'd like to work (such a job)/I will work a job like this to help realize my dream."]