clutch problem

ok this happened i was out of work on saturday, and when i was on the car i noticed that the clutch was half way down i can turn on the car but, the gears dont go in. i also put the car in reverse and tried to turn it on and it would roll back i also tried in first and and the car rolled forward. <<(the car was off when i put it on gear then tried to turn it on) so should i replace the clutch or what could be the problem? my car is an 87 mazda RX7 N/A with hydraulic clutch

Is the clutch pedal working normally?
You should be familiar with how it engages, is it different?
Describe please.

you say that when you turn the car on in gear it rolls with that gear, now is do you have the clutch pedal pushed in or not ?

You should check the fliud in the clutch resivour (if it's a hydro), and if it's low or there is none you need to bleed the clutch or adjust the cluth calbe if it's a cable tranny.