It's really easy to learn. You only really need to be worried about code if/when you start ASM, but you don't even need to do that right now, since you can just ask txin to make you hacks there are a ton of hacks readily available.
It's not really easy to mod cave story without touching the tsc scripts of maps, but it's worth learning really. And honestly, if you can't really learn a programming language at all, you would easily stub your toe at game design unless you exclusively do art or music or such (though you would need others to do the rest).
The best thing you can do is to just try to edit random pieces of the game's tsc scriptsand take a look at some guides like this one.
It shouldn't be too hard to edit things like dialogue.