Need some help on my car?

i just bought a car last week its a 2000 kia sportage. i just got it legal and inspected and everything, they said everything was fine, but where i live they only do the safety inspection. anyways since two days ago i realized that when i turn or step on the brakes it sounds like underneath the car rattles, its not very loud but it still concerns me, and i know my belt squeeks all the time, it started doin that a few days ago too. so i was wondering what could be the rattling noise, it sounds like something loose but im not a mechanic so i could be wrong.