Slave cylinder would be the first thing I'd check cause it's the cheapest bit to fix.

 

The slave cylinder disengages the clutch.........it doesn't engage it. If you have air in the system, or a bad slave cylinder...when you press the clutch pedal to the floor, noting happens....it's like you are not pushing the pedal in...i.e, the clutch stays engaged.

When you bought the car did it have this problem? Sounds like you are going to need to replace the clutch.

 

With the car clearly in gear, and your foot off the clutch, and with your foot on the gas does the engine increase speed but it goes nowhere? Then yes, probably a broken clutch pressure plate.

 

....or your shift linkage is broken and you're in neutral. Can you feel the shifter going into a gear?

 

 

It's not that bad of a job if you are mechanical and have the tools. If you're not going to pull the engine for the job get the strut tower engine brace to support the engine from the top. I just did the clutch and installed a LSD while I was at it. Watch the MOD mini video on YouTube. That's what I did before proceeding. I also made some long guide bolts for reinstalling the transmission, which made for aligning the transmission to the engine to re-butt it a breeze.

 

 

They say it's easier, but I didn't find this way difficult. here's the guides I used that made it a breeze:

 

It's easier to just pull the tranny. Not a super hard job.....just takes a lot of time. It makes it much easier if you have a big floor jack and/or engine hoist to help support things when you pull the transmission off of the motor.

​​​​​​ Take pictures as you go, it makes getting everything back to where its supposed to go easier. Lots of how-tos on the forums (I think I even did one).