If you're running the Jelly Palace levels, you'll find you don't need much shadow or elemental resist. It's mostly normal or normal/piercing. It's also about not getting hit in the first place if you can possibly avoid it. If you're sword focused, the Wolver armor set should be more than suitable.

Outside of that, Elemental damage is probably more common, and harder to avoid. Once you learn how to approach them, most things that deal piercing damage in T2 are not as much of a threat as the random gunpuppies and retrodes that like to sneak hits in from across the damn screen. As far as shadow defense goes, my particular tactic is to just avoid Fiend levels at all costs if I can help it, although making/leveling some shadow defense armor is my next little project now that I have my T3 clearance. It wasn't so much of an issue before, but now that devilites actually deal shadow damage with their projectiles, I find them much more difficult to handle. Most undead are far easier to deal with, so I tend not to get hit as much, if at all.

Honestly, you'll eventually want a few different sets of armor (and a wide arsenal of weapons) so you can customise your loadout according to the tier you're about to visit. Remember that you can change your equipment at each "town" and Terminal depth. Initially, I'd recommend getting a good set of slime-bashing gear and visiting Jelly King often. It's a nice predictable run that's always available, and it's quite profitable. There are better ways to turn a profit in T2, but they involve cherry-picking specific levels, and the gear you'll need will vary depending on what strata the current gates are composed of.

Weapon-wise, if you're still running with the default 2 weapon slots, you'll generally want to carry at least one normal-damage weapon, so you aren't caught with your pants down. The Calibur is actually a very good sword, with perhaps one of the best charge attacks in the game, so I'd hold onto that and use your second weapon slot for a Strata-specific weapon. I'd recommend an elemental alchemer of some type, or a specialised sword if you're not happy with a gun. The Brandish and Sealed Sword lines have the advantage of being split damage, so they're reasonably effective against enemies that resist their non-normal damage type. The Flourish/Snarble Barb is pure Piercing damage though, and you'll not want to be poking it at Jellies and Constructs. The same is true of the Alchemers, if you're using one as a sidearm you'll want to make sure your other weapon doesn't also suffer against enemies that might resist it.