I see that you've decided to save up for a camera. That's cool, but I know budget is still gonna be an issue, so I highly recommend having a look at refurbished DSLRs on websites like KEH and obviously eBay. A few things to keep in mind:
If the camera is too old, it may not have video capability. Do your research before you buy, but there's definitely no need to spend a ton of extra money on a brand new camera. Save your cash to spend on equipment that's going to help you in other areas of capture, like a good microphone, a solid kit of lenses, lighting equipment, and stabilization accessories such as tripods, shoulder rigs, and rail mounts.
Canon is the popular choice for DSLR video, mainly because of their superior autofocus and better silent motor technology, but it's a great idea to use manual focus and an auxiliary microphone anyway for best control and quality results. So what you end up doing is probably going to override all the benefits of Canon, leaving you with its inferior dynamic range as compared to Nikon.
Vintage manual-focus prime lenses (meaning fixed focal-length as opposed to zoom) are your best value for quality glass. Zoom lenses cost a ton of extra money and almost always deliver inferior results. Nikon made some great primes back in the day which are very affordable on the used market. They'e still compatible with their current DSLRs, due to the fact that they've been using the F-mount system since the mid-50s. Canon, on the other hand, has changed their mount several times, so there aren't a lot of used lenses that are easy to get your hands on, offer manual iris control, and will fit the current DSLR system. However, since Canon's flange distance is slightly shorter than Nikon's, you can get an F-mount adapter that'll allow you to use old Nikon lenses on a Canon body, so no matter whether you get a Nikon DSLR or a Cannon, it's a good idea to build a kit of Nikon F-mount lenses.
There are two different sensor sizes for DSLRs: APS-C, aka "cropped sensor" is roughly 2/3 the size of CMOS, aka "full-frame," which is based on the classic 35mm format. You need to know what sensor size your camera has when you search for lenses. The more affordable DSLRs tend to have cropped sensors, so you need to multiply focal length by the crop factor (roughly 1.5). For example, if you have a cropped sensor and want the field of view of a standard 50mm lens, you need to use something like a 35mm lens (35mm x 1.5 = 52.5mm, so that lens is going to give you a little tighter field of view than a 50 would on a full-frame camera).
Rode makes a very affordable microphone that mounts to the camera's hot shoe (flash mount), which is a popular solution for quality audio recording. There are other brands, of course, but it'll be an essential upgrade to your audio quality. If you can find one used, even better.
So I'd say bare minimum kit would be a used DSLR (I'd choose Nikon, but maybe I'm biased. How much you spend is going to depend on how important it is to have 1080p or 4k capability, and how important it is to have a full-frame sensor.), a vintage 50mm lens (35mm if the camera body has an APS-C sensor - of course your go-to focal length is going to be a matter of personal preference), a hot-shoe mounted microphone, and of course storage (SD cards, flash cards, or whatever works in your particular camera) and at least 2 batteries (3 or more would be ideal for a full day's shooting, buy them on eBay and not from a battery store for ridiculous savings, as in $5 as opposed to $90 - but pay very close attention to product photos and make sure they at least appear to be authentic). You can probably get all that without spending more than $800, and you get a kit that can keep on expanding as you collect more lenses (a wide-angle for environmental shots and shooting in cramped spaces, a telephoto for close-ups), back-up bodies for second angles, etc. Also, it'd be a good idea to look into tripods and shoulder rigs for stabilization, depending on your stylistic preferences.
If there's one thing that's vital for you to take away from this, it's that you should never buy new gear when you can save a ton of money getting it used.