Any DSLR or mirrorless is going to be more than good enough for a beginner. This is because of the main features that they all share such as full manual exposure along with aperture & shutter priority, program mode. They all have manual focus, auto focusing single-shot and continuous modes, too. They all have the ability to get various shots by utilizing technologies that aren't found in any other types of cameras such as point-and-shoot cameras, super-zoom cameras (which simply "look" like a DSLR but are really just point and shoots), and any smartphone.
Now, with that said there are going to be some specific models that will be better for some users depending upon what they're doing. For example, those who need video capabilities will want to go with a mid or high-end Canon, Sony or Panasonic model because of their great video capabilities. For the same reason, those who need really good video performance would be best served by avoiding Nikon, Pentax and Fujifilm cameras. Another example would be someone who constantly shoots hand held in low light. Those shooters will need image stabilization. While in-lens solutions (ILS) from the likes of Canon and Nikon work very well, in-lens stabilization is not as good as in-body image stabilization (IBIS). For one, ILS requires specific lenses while IBIS works with any lens including old lenses from the 70s (such as with Pentax). ILS also require additional lens elements which means lower image quality, heavier and costlier lenses. For this reason, Pentax would be the best brand of DSLR, while Sony would be the best mirrorless option for those who need to shoot hand held in low-light situations.
Overall there are no "bad" DSLRs or mirrorless cameras. However, there are some that do things better than others which means that there are going to be better bodies for each user depending up what they shoot and their overall needs. As a beginner, you probably don't have a real clear sense of what you really like to photograph or what you want to photograph, or what are some of the essential features for those types of photography. Nor are you likely to have a real grasp on the fundamentals of photography both on the technical and artistic side. All of this is fine as no one is born with this stuff already in their head. It takes years to learn it. An entry-level body will be more than good enough for a beginner to use in order to learn those things. And over time, say 1-2 years of constant use, then the user will have a rock solid idea of what they like to shoot, what they want to shoot, and what features that they need to do it.
With this in mind, I'd recommend either a Canon T series such as the T5, T6 or T7, or a Nikon D5xxx series, or the Nikon Z6, or a Pentax K-70, or a Sony A6300, A6500 as really good entry-level cameras. I would skip the Nikon D3xxx series since this is the only line of DSLR without an internal focusing motor.
But what if you already know that you need really fast continuous focusing because you already know that you need or want to shoot things like wildlife or horse racing or soccer, etc...? In this case an intermediate body like the Canon 77D, 80D or the Nikon D5xxx would be much better options than most mirrorless cameras (except for the Sony A9) and any DSLR from Pentax which is known for it's average focusing capabilities. But average isn't necessarily a bad thing, it's just not as good as the better AF systems found in the mid to advanced DSLRs from Canon or Nikon. Of course, if sports or very fast-moving subjects is not your thing, then the Pentax K-70 is unbeatable for its advanced features and overall capabilities.