Got in my truck to leave lowes and I'm pulling out and when I get to a stop sign I push down on my clutch pedal and it goes straight to the floor and stalls out when I start it back up it won't go into any gear unless I pull my clutch pedal up by hand.. Then I can shift in 1st and then it goes all the way back to the floor.. What's wrong???

 

Check for leaks, sounds like you are losing pressure big time. Another member had the same symptoms after he rebuilt his, if no leaks are found check for blockages, might be looking at replacing the master cylinder if no leaks or blockages are present. I'm sure there is a way to test for pressure using the bleeder valve but I am unsure of how to do it.