Could you check and correct my English writing?

I have two things what I want to do after going on to University.
First, I want to join the model United Nations. I want to observe a lot of international issues in different perspectives.
Second, I want to go to Canada to study because studying abroad allows me to broaden my horizons and learn its cultures and traditions. In addition, I will be able to speak English more fluently because I will speak only English during the stay.
In conclusion, I have a lot of goals what I want to achieve and I’m going to continue to make efforts to realize them.

Question

Could you check and correct my English writing?

I have two things what I want to do after going on to University.
First, I want to join the model United Nations. I want to observe a lot of international issues in different perspectives.
Second, I want to go to Canada to study because studying abroad allows me to broaden my horizons and learn its cultures and traditions. In addition, I will be able to speak English more fluently because I will speak only English during the stay.
In conclusion, I have a lot of goals what I want to achieve and I’m going to continue to make efforts to realize them.

emtrivoli · Answer

I have two things THAT  I want to do after COLLEGE.  (do you mean after college, or after high school)

First, I want to join the model United Nations. I want to observe a lot of international issues FROM different perspectives.

Second, I want to go to Canada to study because studying abroad WILL ALLOW ME TO  broaden my horizons and learn ABOUT  DIFFERENT cultures and traditions.

In addition, I will GET BETTER AT  English because I'LL BE SPEAKING ONLY ENGLISH WHILE I'M THERE.

I have a lot of goals TO ACHIEVE, and I’m going to KEEP WORKING ON THEM.

emtrivoli · Answer

do you mean in the first sentence?  don't think of it as what's the 'difference'; it will be easier to think of when to use each word. 
here are some examples: 
A: There are 2 things THAT i want to do today
B:  WHAT are the 2 things THAT you want to do? 
A:  clean the house and go shopping, those are the things THAT I need to do. 
B:  WHAT else?

maybe... we use "what" when we're asking questions. that's something to keep in mind, and should help you.

Deleted user · Answer

I have two things that I want to do after finishing University. 
(I'm guessing you mean finish since you used the word after)

First, I want to join the model United Nations. I want to (also) observe a lot of international issues in different perspectives.
Second, I want to go to Canada to study because studying abroad allows me to broaden my horizons and learn it's cultures and traditions. In addition, I will be able to speak English more fluently because I will speak only English during the stay.
In conclusion, I have a lot of goals that I want to achieve and I’m going to continue to make efforts to realize them.

Deleted user · Answer

I barely had anything to fix. Good job! :DD