From a guitar standpoint:
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Classical vs. steel-string acoustic vs. electric solidbody vs. archtop jazzbox, etc. - all typically strung and tuned the same way, and basic knowledge of chords, strums, scales, etc. will serve you well across each type. But all of the subtlety of technique could not be more different - the approach to strumming for steel vs. nylon string; how you hold your picking hand and whether you rest the meat of your pick-hand palm on the strings to mute them.
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Fingerstyle vs. fingerpicking vs. fingerpicks vs. flatpick vs. slide - all are very different and someone good at one may stink at the others. Btw, “fingerpicking” typically means you have a picking pattern you maintain more or less as you change chords; “fingerstyle” means you don’t use a pick, but don’t necessarily pick in a pattern - folks like Jeff Beck and Mark Knopfler, for instance, seem to just toss their fingers out there and see what happens
And playing with fingerpicks on your fingers vs. just using your fingers (and some folks use their nails and others just the meat of their fingertips…) -
Playing the guitar vs. playing the amp and effects - if you are playing an amp seeking a very clean sound, you are playing the guitar and using the amp to…well, amplify that. If you are playing with a lot of distortion, you are “playing the amp” as much as playing the guitar, if not more - Hendrix and Townshend played their amps more than their guitars. And if you use a bunch of effects - don’t get me started. Bottom line, learning out to sound good with a distorted amp and a tone of effects is completely different from playing a clean-sounding guitar.
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Models - you mention a Les Paul vs. a Telecaster - well, yeah, it can be different enough, depending on what sound you are going for. But a Tele is especially well-suited to country-type chickin pickin and a Les Paul is esp well suited to Sweet Child O’ Mine tubey-sounding lead work. You can use either guitar to play the other style, but it is harder - and so, yeah, learning how to pull the best sounds out of a particular guitar design can be a next order of difficulty. If the guitar has a whammy bar of some sort, you have a whole 'nother level of moving part to learn how to include in your act…
So, yeah, there’s a very wide spectrum of 6-string, guitar-like instruments out there…