The X-T3 is larger and heavier than the other two; it doesn't bother me, but it's something to consider. I actually like the heft and size because I'm using the longer zooms a lot.

The X-T30 has a nice feature for an absolute beginner: an AUTO lever that lets the camera do all the thinking. It also has "scenes" like portrait, landscape and sport to help you take good photos right away. The X-T3 doesn't have an AUTO lever. The X-S10 has an AUTO dial setting that automatically selects a scene.

The X-T30 and the X-S10 share the same electronic viewfinder. The X-T3 has a higher resolution electronic viewfinder (3690K dots vs 2360K dots) and higher magnification (0.75x vs 0.62X). I use the EVF much more often than the LCD and appreciate the quality of the EVF on the X-T3, it's a joy.

I think it's a difficult decision between those three cameras. Whichever body you choose, I agree with a previous post that the 18-55mm is a fine lens to start out with, it was the one I got with my X-T20. I have a variety of prime lenses now, but the 18-55mm isn't leaving.