How to celebrate Chinese New Year?

I think you can learn to say some Chinese New Year greetings, that's what every Chinese do on that day.
You can say these to him:
"Shin nian kuai le" 新年快乐, means happy new year
"shen ti jian kang" 身体健康, means having a healthy body
"bu bu gao sheng" 步步高升, means getting promoted or going higher
"wan shi ru yi" 万事如意, means having everything goes fine

You can copy and paste the chinese words on google translate to learn them, the chinese words are pronounced pretty accurately there.

For decorations you can write the above chinese greetings vertically on a red rectangular paper(that's another tradition) and stick on the walls or simply write the word 福 on a red rhombus shaped paper and stick it inversely on doors. Better use golden ink. Search 春貼 on google for some examples.

Wear red or golden colour stuff on that day. Chinese traditional food would be too hard to make, try to search in china town.