Silverado_L31

I just bought a 2000 camaro ss with 6 speed, and noticed after about two times of driving it after i get on it and then put my clutch in slowing down i hear a kind of clunking noise like something is trying to rip a little piece off then the noise goes away and it seems like its fine. Also when shifting it almost seems likes its tough getting it out of the gear and into the next. I almost think it sounds like the throwout bearing or something but not sure? Any Help or suggestions would be greatly appreciated thanks a lot.