Just started Toribash and I'm already lost. I have no idea what joints can make a punch, kick, jump, etc..

I need some help, what can I do?

The best thing to do is just mess about with the different joints until you figure out how it works, that's what i did anyway.

I normally, whenever I get into a match, randomly just click joints, press space, and watch that happens.

I know there must be SOME joint presses that can make a punch or a kick, etc.. I can work from there after that.

ok for a basic kick press c (hold all)

then do extend both glutes and extend left ankle

Best way is to make up some openers in single play and then try em out online.

Don't listen to these idiots. (Not fawflaw, he posted sensibly)
Best thing to do is experiment and practice in singleplayer, and then take those skills to multiplayer.
Right, you wanted to know how to do a basic punch.
Do these:
Rotating chest right.
Extend right pecs.
Contract left pecs.
Other things for stability such as holding knees and hips etc.

Space until you are fully rotated.

Then, basically just inverse every join apart from
the stability joints.
eg. Left rotating chest.
Contract right pecs.
Extend left pecs.

Please don't hesitate to use the relax state, as many think it is the superior state. Also, check the forums regularly for tips and help.
Hope I helped.
~Dobby

Slow it down... Don't start with the hardest! Well, jump is sorta easy but kicks are Medium and punches... lets just say you got lots of stuff to learn before punches. Also you got some tutorials in-game, just go to the menu than press fight school, and learn the basic toribash stuff.

btw yea punches are complex. even advanced players take a lot of time to perfect it. so just worry about kicking, but don't expect to be able to like decap rite off the bat heh;)

Well This is pretty much to the point

Contracting Pecs makes your arms close in together
Extending pecs makes your arms go father apart.

Raising shoulders make your tori raise his arm
Lower shoulders make your tori lower his arm

Extending glutes make you spread your legs ( like a Split )
Contracting glutes make you close your legs ( like crossing them)

Extending Hips make you kick your legs out
Contracting Hips makes you kick your legs backs

Extending knee straightens your knee
Contracting knee makes you close your knee

Extending ankle makes your ankles go down and your tori gets higher ( like you on your tip toes)

Contracting ankles make your ankles go up ( Good for spinning )

Errrr no. Punching is really easy.

What dubby said.
Rotate your body in one direction and then counter rotate it. Make sure your legs are on the ground and not moving so you can get more power out of your rotation.
When you are punching you will be standing on one leg and use the other one to either balance or boost even more power into it (or preferably both).
In the provided replay I'm standing on my left leg and extend the hip. By extending the hip (in combination with the glute) I'm pushing the leg into the ground which makes me rotate in the punch direction in gives therefore more power.
The other hip is contracted. By counterrotating the other hip I'm adding to the power of the move and I'm also using it to not fall to the left. The key to a punch is a solid base of your legs. The more they will rotate but stay at the same place, the more power will move into the spin of your body.

Sounds more complicated than it is. Spread your legs, rotate your body, counterrotate everything to punch.