~10 min
Piglins stay neutral toward you as long as you're wearing at least one piece of gold armor; take it all off and every nearby piglin turns hostile. Even in gold armor, though, you can provoke them: attacking one, breaking gold-related blocks nearby, or opening or breaking any chest all trigger hostility, and an attacked piglin calls in others from a good distance away. Offer a piglin a gold ingot, by right-clicking it or dropping the ingot nearby, while it isn't angered, and it barters, tossing back a random item after a several-second pause. A piglin that ends up in the Overworld or the End turns into a zombified piglin after about 15 seconds.
Ghasts are the large floating mobs that shoot explosive fireballs from a distance, mostly over open Nether wastes and lava seas. A well-timed hit on an incoming fireball, with a sword swing or an arrow, knocks it right back toward whatever fired it, which is the standard way to damage or kill a ghast without ever closing the distance. Nether fortresses are the tall brick structures where blazes spawn, the only source of blaze rods, which craft into blaze powder, the key ingredient in both eyes of ender and brewing stands. Wither skeletons also spawn there, dropping the skulls used to summon the Wither later on.
General Nether survival matters here too: since it's built mostly from netherrack, soul sand and basalt over huge lava seas, staying off unstable ledges and building safety rails around any drop matters even more than in the Overworld. Bringing blocks to bridge over lava is worth it, since falling in is far more common here than accidentally mining into a lava pool back home. Fire resistance potions make both lava crossings and ghast fireballs far less dangerous, and are worth brewing before any serious trip, especially one aimed at a fortress.
The fireball gets deflected back toward the ghast, which is the standard way to damage or kill one at range.