traveling

I will graduate from the university and work at in an office in April. I went to South-East Asia for 2 weeks before working and went back to Japan the day before yesterday. I could see saw many a lot people from several different countries, such as France, Pakistan, and Vietnam. I spend spent great days there. Even after beginning to work, I want to take days off regularly and to go around the world. In Japan, it is sometimes really hard to get days off, but I will give it a try.

traveling

I will graduate from the university and start work at an office in April. I went to south-east Asia for 2 weeks before starting working and came went back to Japan the day before yesterday. I could was able to see many people from several countries, such as France, Pakistan, and Vietnam. I spend spent great days there. Even after beginning to work, I want to take days off regularly and go around the world. In Japan, it is sometimes really hard to get days off, but I will give it a try.

The first sentence sounded like you were graduating from work as well in April, writing "start" clears that up.

At the end of a list of items, the last item you will usually write 'and' before it. 

And "spent" is the past-tense of spend

Good Job. Glad you had a good trip. Hope you new enjoy the new job!