hmm if it goes in gear when the car is off i am not sure
if you turn the car off, put in reverse, foot on clutch and start car
can you do that ok? then put in 1st then try and put back in reverse
wack the car in to 4th, handbrake right up and try and pull away slowly, if she stalls then clutch is fine, if she slips then you may need a new clutch mate