Alrighty, here's the story!! So after setting my timing and getting my  rt2 running, I giddily tried shifting into first aaaand.....zilch. Does anybody know how I can go about troubleshooting? Any advice would be greatly appreciated!!!

Edit: I just thought I should add that the shift lever moves up and down nice and clicky. It does run so I'm thinking of taking a look at the clutch and seeing if it's stuck on.

When you say you shift into first, are you pulling in the clutch, shifting into first, and the engine dies? If so, you probably have a stuck clutch. You could check the adjustments, but if the bike has been sitting for a long time, the plates might just be stuck together.

Can you click it down to first then up through the gears without motor running, just moving the bike forward & back an inch or two for things to line up.
Here's link to the items that come into play. Unless clutch it totaly burnt out or stuck open, but both unlikely causes.
www.partzilla.com/catalog/yamaha/motorcycle/1972/rt2/shifter-a
www.partzilla.com/catalog/yamaha/motorcycle/1972/rt2/shifter-b

It won't change gears :( . I pull in the clutch lever and push the shift lever down to move into first and it just chills out in neutral despite the rude things I say to it. It has been sitting for a long time though so it wouldn't surprise me if all sorts of things were siezed ( literally pulled it out of a field )

When I first got my DT2 it would start up just fine but when I pulled the clutch in, put it in first then let out the clutch I got nothing!  It would even just slightly like it was engaging.  I ended up changing out the clutch friction plates, clutch plates, and clutch cable.  I also changed out the plastic piece (not sure what it's called), in the left side case where the clutch cable goes in, because that was split (see picture), you can get it from KDI if you need it and the adjuster bolt and nut can be found on ebay.  After all that it works great!

 

So I took a little bit of time to look into how the clutch works and I see that it has a little push rod that gets actuated by the clutch lever. My question is..... Is that push rod supposed to be able to move deeper into the clutch? I'd imagine, if its goal was to compress clutch plates together, there would be a bit of play into and out of the shaft.....mine just kinda doesn't do that. Is that normal and I have to keep researching until I understand clutches better? Or is there supposed to be movement in there that isn't?

If you're talking about the push rod on the left side it actually pushes the clutch disks apart, disengages it, and no there shouldn't be any play and you can't push it in by hand. 

Yes, there should be a little movement there. Undo the locking nut and screw/unscrew as necessary.

You can't push the rod with your hand, there's a little worm drive mechanism in the side cover that pushes it in. What it does is actually uncompress the plates , which are held together with springs However even if it pushes and your plates are stuck together, the clutch will still not disengage.

What I did when I first got my CT-1 running, and I don't recommend you do this, is I held the brakes as I sat on the bike, revved the engine, pulled the clutch in and pushed it into first. That broke the plates free. But again, I wouldn't recommend that, as you could break something. Eventually I took the right side cover off and rebuilt the clutch, is which is probably what you're going to have to do. As it was, it was slipping quite a bit when I was riding.

What the OP described in his first post is exactly what I had when I first got my DT2, I replaced everything from the clutch cable to the worm gear to the clutch disks, I now have a perfectly functioning clutch...

EDIT:  his problem is not the sticking, he has no clutch.