1. I'm excited because I get on the airplane for the first time.
2. This is my first trip abroad, so I am very excited.
3. I got off the airplane at the airport.
4. I waved on the laddle to the airplane.
5. I was excited because I could go abroad for the first time in my life by plane.
6. I arrived at Kimhae Airport and got on the plane. I was satisfied because I had wanted to go abroad to study English.
(Would you checked The English expressions?)
I don't know what you meant to say in # 4, because "laddle" is not an English word.
The rest are correct -- but # 3 is unncecessary. The only place to get off an airplane is at an airport.
Also, "happy," or "thrilled" would be better than just "satisfied" in # 6.
Sure! I can help you check the English expressions in your sentences. Here are the corrections:
1. I'm excited because I'm getting on an airplane for the first time.
2. This is my first trip abroad, so I am very excited.
3. I got off the airplane at the airport.
4. I waved goodbye to the airplane.
5. I was excited because I could go abroad for the first time in my life by plane.
6. I arrived at Kimhae Airport and boarded the plane. I was satisfied because I had wanted to go abroad to study English.
I have corrected some grammar and vocabulary errors in your sentences. Keep up the good work!