"因為是第一次罰單,期間和警察懇請是否能給warning;" Did you offer something to the officer in exchange? Did you make a comment that remotely suggested something?
Assault can be verbal or physical. You need read exactly what the charges against you.
If you are convicted, you can go home possible with tax payer's expenses.
PS it is not police procedure to grab somebody from their car. He suppose to ask you step off the car and conduct a search. So either you BS here or, you dont know what you did. BTW, did you drink, smoke or take something?