Pontiac Firebird SHIFTING problem?

I have a 1995 Firebird 5 speed manual. When I start the car and it's cold, it shifts okay, but when I drive a while, it gets harder to shift and when I wanna go on R, it makes a noise. I just wanna know what can be the problem. Sometimes there is this smell also when I drive for a while. My dad says it needs a new clutch kit. I just wanna know can something else be the problem?