How do i get my new cat use to me?

i got sunday, from this lady she said shes lovable,n blah blah blah...but my mom said she had open the cage we got her in. and she just took off in the house and shes been hiding. last night she was meowing and she was puttin her paw underneath my door and i opened it and she took off to her spot i guess. and then today i was like im gonna find her!!! and [we have a buncha junk in our USED TO BE garage, now my parents just throw junkk in it] so i finally got her. i put her in a empty room...she was rubbing all against mee and all the stuff on the floor lol...but shes like so ready to take off if i open the door to the room to go hide...how do i get her not to hide?? shes 4yrs old.....