Don't bother looking up posts about diodes. Quite frankly, they're not really relevant to what you're asking. Interesting stuff if you're an electrical engineering geek, and good to know about if you're running a rig with multiple batteries, but for what you're talking about, not much use.
So now let's talk about your situation. You've got a cheap rig, with no wiring, no battery mount, and no "starting point" for powering anything. In some ways, that's good, since you can build in what you need. It can seem a bit daunting though. Hopefully I can break it down and make it a tad easier for you to wrap your head around.
If you want your batteries to last you any time in your professional career (which I presume you would, since they're expensive to invest in), you have 2 choices for battery type: V-Lock (like IDX and RED batteries, among others), and Anton Bauer (known generically as 3 stud). There are pros and cons to both mounts, and both mounts have options for you to get name brand or generic batteries (though you'll find more generics as V-Mounts). Both will be expensive, especially if you buy name brands. Quite frankly, I can't comment on generics, since I've only ever used name brand Anton Bauer batteries on my rig, and name brand IDX on the only other rig I've had much time prepping and flying. To pick which mount style to go with though, you can either pick based upon what gear you end up with (for instance, if you stumble across a bunch of used batteries, like I did relatively early on in my career!), or you can pick based upon what will be most useful for your career. Pick based upon what people in your area use - then you can swap batteries with friends, rent them to other people, etc... If all the cameras you use are V-Lock, using a V-Lock system on your rig will let you borrow camera batteries if you're ever in a pinch, or vice versa. So, that's your first decision.
Next up, buy a plate and figure out how to mount it on your rig. I'm guessing your rig didn't come with provisions for this, so you're going to have to DIY something. That's a good way to get started modding your rig though - something you'll end up having to do a lot of with cheap rigs. In terms of plates, especially with V-Locks, the name brand IDX plates are great. Some knockoff plates have bad connection issues (see all the issues with REDs losing power when their batteries get knocked). AB brand plates are also incredibly sturdy, and a great investment. I have some that must be 30 years old at this point, and they still work fine.
Batteries - For the type of work you will be doing in school, and just for ease of use, don't buy gigantic bricks of batteries (like the Anton Bauer ProPac, for instance). Buy something manageable, and with a weight in the 2-3 pound range. Anything heavier than that is going to be a bear to balance on your rig. How many to buy? If you're going to be working professionally, you need to add up all the power consumption of the devices you're going to be powering, and figure out how long the battery you're planning on buying will last with that load on it. Make sure that you've got enough juice to get yourself through a day. I generally try to have 3 sets of batteries (for my rig, that's 3 sets of 3 batteries, for yours that would be 3 batteries), and enough charger positions to keep all of them that are not in use topped off. That way, I can just send an AC to go grab me a hot brick off the charger, and the depleted one goes right back on in its place, to be ready to use later in the day. Don't be afraid to buy too many though - running out of power is an issue you want to avoid.
Now, you've got batteries, some amount of chargers, and a plate on your rig. You can either now start wiring up your rig and adding junction boxes, which takes you down a whole DIY path, or you can do it the easy way and just string up a cable from your battery to your monitor. Any battery plate should have a D-Tap or Power Tap connector on it (different brand names for the same plug). It should be easy enough to acquire a cable to go to your monitor from that plug. String it up, and your monitor will be powered. If you want to power more things, you can either go to having a power distribution system in a junction box, or get a D-Tap splitter.
Now, for your specific needs, you talk about powering a monitor (as I showed in the last paragraph, very easy), as well as powering a DSLR. I will say this - don't bother powering the DSLR. The power adapters for DSLRs are expensive, you need one for each different type of camera, and DSLR batteries are dirt cheap. Buy 6 or so batteries and 3 chargers, and work for the whole day on what you would spend on one more battery - Seriously!
As you start working your way up though, you will want to run a follow focus. It's unavoidable - working without one sucks, and even though you may have to bare it until you can afford to rent/borrow/buy one of your own, you should prepare for its eventual use. For that, you need power on the top of the rig. You can either do this via running a cable up the post, which would have to be a coiled cable to accommodate the extension of the post, or you could go the half-assed route and just string a power cable from the battery, past the back of the monitor, and up to the top of the rig. It's not pretty, but at least in that configuration, it should never interfere with the gimbal or your hands. I'll admit that when the power wiring on my sled decided to die on me in the middle of a shoot flying a BL4, I strung up a whole bunch of cables that way to power everything. It works.
Hope that helps. Yeah, you'll probably get some blowback from buying a Liang. They're not the best rigs, and the engineering behind it is... questionable, to put it mildly. But, if it gets you started practicing, and lets you get comfortable enough to move up and buy a real rig when you're ready to move your career in that direction, I say kudos to you.