First off, since you have friend that is a Canon shooter, going with Canon can have benefits in terms of swapping lenses and accessories that choosing another system may not allow.
For your stated use case (landscape stills), here are the biggest differentiators between the EOS Rebel T6/1300D and the EOS Rebel SL2/200D:
- The 24.2 MP for the 200D versus 18 MP for the 1300D. If you plan to display any of your images in large sizes, this could make a significant difference.
- The 200D has spot metering in addition to partial, center weighted, and evaluative metering modes found on the 1300D.
- The 200D offers ISO settings in 1/3 stop steps from ISO 100 to ISO 12800 and ISO 25600 in 'normal' mode plus 'H' extended mode equivalent to ISO 51200. The 1300D only offers whole stop ISO settings between ISO 100 to ISO 6400 with 'H" extended mode equivalent to ISO 12800. The higher ISO settings probably aren't a consideration for landscape photography, but the finer steps between the lower settings might be.
- The viewfinder of the 200D is about 9% larger than the viewfinder of the 1300D. Both give a 95% view of the frame, but the magnification of that 95% is greater in the 200D's viewfinder. If you wear eyeglasses, the 200D has a slightly wider diopter correction range than the 1300D (-3 to +1 vs -2.5 to +0.5).
- The 200D has a dedicated depth of field preview button (allowing the 'Set' button to be used for other functions). To get DoF preview with the 1300D, one must remap the 'Set' button to that function at the expense of using that button for another function.
- The 200D has a vari-angle tilt/swivel touch screen. The 1300D has a fixed LCD screen that is not touch sensitive.
- The 200D offers a few more "scene" modes and in-camera "creative filters" than the 1300D, as well as in-camera cropping and resizing not offered by the 1300D.
- The 200D features Canon's relatively new multi-shot noise reduction as well as in-camera lens correction for peripheral illumination, chromatic aberration, distortion, and diffraction. Of the above, the 1300D only offers lens correction for peripheral illumination. Not a factor at all if you are shooting raw files, but might be an advantage if you are wanting to share jpegs quickly.
- The 200D can shoot at 5 frames per second, the 1300D maxes out at 3 fps. If you plan to do exposure bracketing, such as for HDR, the faster frame rate will help reduce the effects of any motion in the scene.
- The 200D includes Dual Pixel CMOS AF, both for stills and movies, in Live View mode. The 1300D does not. Combined with the touchscreen features of the 200D, this could make selecting focus distance for landscape photos more flexible (in terms of where in the frame you want to focus) and faster and easier with the 200D than the 1300D.
- The 200D gets about 30% more frames out of a fully charged LP-E17 battery than the 1300D get out of an LP-E10 battery at 23°C. At 0°C the 200D is rated for 50% more images than the 1300D.
- The 200D is slightly smaller and lighter than the 1300D, but the differences are fairly miniscule.
Overall, the most significant differences the 200D offers over the 1300D for shooting landscapes are higher resolution, a vari-angle touch screen, Dual Pixel CMOS AF in Live View, and several in-camera features that would come in handy when producing jpegs straight out of the camera. For extended hiking trips, the extra battery life will also come in very handy.
Whether that is worth the extra $200 is something you will have to decide. You'll need to leave room in your budget for a few additional accessories such as a tripod (or monopod in a pinch) and a few filters.
In terms of the lens:
The current 18-55mm kit lenses are a lot better than those from a decade or so ago. Most of the improvements seem to be more in the area of quality control during manufacturing than in actual improvements to the optical formulae. But for whatever reason, they are demonstrably better. Either the EF-S 18-55mm f/3.5-5.6 IS II or the newer EF-S 18-55mm f/4-5.6 IS STM are about the same optically and are adequate for shooting landscapes in daylight. These are some of the best values in terms of quality and versatility per dollar that you'll find. (Other manufacturers' 'starter kit lenses' are similar - they're practically giving them to you to get you to buy their camera and get hooked into their system).
Having said that, though, these are not some of the best lenses you'll find. They're starter lenses. One of the things you will soon discover regarding lenses is that quality and versatility are often opposed to one another. The 'best' highest quality lenses do only one or perhaps a handful of things very well. But they are not well-suited to many other photographic tasks. The most versatile lenses do many things acceptably well, but they don't excel at any of them.
For a beginner, versatility is not necessarily a bad thing, though. It allows one to explore and learn and discover where one wants to go when the time comes to buy nicer and more expensive and more specialized lenses.