In response to a few:

a. I'm a big fan of the DGBE tuning (so yea, like you took sidecuts and snipped the EA off the top of your guitar); I like this because 6-string skills transfer, and I've messed around quite a bit on a baritone ukulele tuned the same. You mentioned being a beginner, so you also get a lot of 1-finger & 2-finger fretting this way.

b. BUT just cutting the top two (or bottom two depending on which terminology you use) off your Dreadnaught will not mirror the effect of that cool sound of a vintage tenor guitar (won't be as plucky and folky...will sound more like a flat guitar...which can still be a cool sound...).

c. AND cutting the strings on a standard 6 string won't solve the size problem; you'll still have to stretch your fingers to the neck size of the standard guitar (PLUS you wind up with a weird bottom-loaded looking instrument, where a true tenor guitar will center your 4 strings with the sound hole).