1) I go by bus. I go by rickshaw.
We append ने(ne) to सामान्यरूप of the noun.
i.e. We say बसने (basane) रिक्षाने (rikShAne)

I go by bus -> मी बसने जातो (mI basane jAto)
He goes by plane ->तो विमानाने जातो (to vimAnAne jAto)
He walks to office / He goes by foot -> तो चालत जातो (to chAlat jAto)

2) I have a car. He has two brothers.
I have a car -> माझ्याकडे गाडी आहे (mAjhyAkaDe gADI Ahe
He has two brothers -> त्याला दोन भाऊ आहेत (tyAlA don bhAU Ahet)

For more details of such sentences refer lesson
“To have” to indicate possession and relation

I did not have time -> माझ्याकडे/ मला वेळ नव्हता. (mAjhyAkaDe/malA veL navhatA )
I do not have time -> माझ्याकडे/मला वेळ नाही. (mAjhyAkaDe/malA veL nAhI )

3) What have you prepared for lunch today:
आज जेवायला काय केले आहे.(Aj jevAyalA kAy kele Ahe.)
आज काय स्वयंपाक केला आहे ( Aj kAy svayaMpAk kelA Ahe )
What have you prepared for breakfast today: आज नाष्त्याला काय केले आहे (Aj nAShtyAlA kAy kele Ahe )