most of the time I'll be shooting portraits and landscapes.

I think that applies for most people/casual shooters. :)

On a serious note, if you really prefer an ideal kit to cover both of these opposing fields of photography, you will probably want to consider a high-end compact with fixed zoom lens, or an interchangeable lens camera system ("ILC") so that you can use a high-quality wide lens for landscapes, or a telephoto lens for portraits.

In addition, there's also the saying "the best camera is the one you carry", so you should also evaluate your everyday carry and see how well a DSLR, mirrorless or high-end compact can fit, if you intend on bringing it everywhere with you. The recent entry-level DSLRs have drastically reduced in size and weight compared to their equivalents a few years ago, so you may not want to write them off too early.

I agree with @inkista's excellent answer that you should choose a camera that gives you full exposure controls - manual or aperture/shutter priority modes come to mind. This is important to learn the basics of understanding photography, as you get to appreciate the effect of using a large aperture for shallow depth-of-field, or long exposure for 'silky' water effects.

RAW output is recommended because you often find more 'headroom' inside these files to either post-process with finer noise-handling controls, or expand the dynamic range (in layman terms: "stronger colors"). If you are perfectly fine with the JPEG output straight from the camera though, then I feel this is only a small bonus.

Rounding back to the first point about lens choice, sure, one can always crop from a wide-angle shot to get pretty good portraiture shots, but that involves extra processing at the end of the day, and also assuming you are still satisfied with the remaining image resolution left. This is why I started my answer with the suggestion of a two-lens option if you go the "ILC" route, in order to make the most of the camera's sensor.

most of the time I'll be shooting portraits and landscapes.

I think that applies for most people/casual shooters. :)

On a serious note, if you really prefer an ideal kit to cover both of these opposing fields of photography, you will probably want to consider a high-end compact with fixed zoom lens, or an interchangeable lens camera system ("ILC") so that you can use a high-quality wide lens for landscapes, or a telephoto lens for portraits.

In addition, there's also the saying "the best camera is the one you carry", so you should also evaluate your everyday carry and see how well a DSLR, mirrorless or high-end compact can fit, if you intend on bringing it everywhere with you. The recent entry-level DSLRs have drastically reduced in size and weight compared to their equivalents a few years ago, so you may not want to write them off too early.

I agree with @inkista's excellent answer that you should choose a camera that gives you full exposure controls - manual or aperture/shutter priority modes come to mind. This is important to learn the basics of understanding photography, as you get to appreciate the effect of using a large aperture for shallow depth-of-field, or long exposure for 'silky' water effects.

RAW output is recommended because you often find more 'headroom' inside these files to either post-process with finer noise-handling controls, or expand the dynamic range (in layman terms: "stronger colors"). If you are perfectly fine with the JPEG output straight from the camera though, then I feel this is only a small bonus.

Rounding back to the first point about lens choice, sure, one can always crop from a wide-angle shot to get pretty good portraiture shots, but that involves extra processing at the end of the day, and also assuming you are still satisfied with the remaining image resolution left. This is why I started my answer with the suggestion of a two-lens option if you go the "ILC" route, in order to make the most of the camera's sensor.