YOU SAID:

i was at the mall with my friend and we got mcdonalds

INTO JAPANESE

私は友達とモールにいて、マクドナルドを買った

BACK INTO ENGLISH

I was at the mall with my friends and bought McDonald's

INTO JAPANESE

私は友達とモールにいて、マクドナルドを買いました

BACK INTO ENGLISH

I was at the mall with my friends and bought McDonald's