Second Mock Interview's Learning Point

I said 'Few days ago, I planned to go to vietnam.'
-> I should have said 'A few days ago, I planned going to vietnam.'

'It was complicated than I expected.'
-> It was more complicated than I expected.

'Yesterday, we finished our final presentation. So there is 80%sure to go vietnam.'
->So I can say there is 80%sureness we can go to vietnam.

'I will prepare various kinds of task which will give the students.'
-> I will prepare various kinds of class methods and tasks which will help our students      improve their ability.