This is probably a classic question about in-game information rather than game mechanics that you should ask in-game allies and helpful higher level characters. Some general observations from another newbie follow:

If you search through the various merchants in the game, in all the cities and markets outside of them, you can acquire fairly decent stuff at a low level.

Other than that, sources of 'shiny' armor are basically what people loot from higher level corpses, what they receive as gifts, and what they loot from people they kill, and what they find lying on the ground because a higher level character killed a mob wearing it but didn't need it/care what happened to it. It also derives what people are skilled enough to run for themselves, but as a newbie you (and I) don't have access to that by definition.

Complete sets of shiny stuff happen when a high level character dies, the killer butchers the corpse or doesn't stick around to guard it, and a lucky low level character picks it all up. They also happen because very good player killers at low levels (or any levels) are able to kill a lot of characters and acquire the one 'good' piece everyone seems to find around. By definition, the good players are skilled at avoiding getting killed by gangs of less skilled players and often let the other skilled players keep most of their stuff via an explicit or implicit form of detente (and also because they just don't need most of it having amassed what they want).

Very rarely, you'll find a crazy altruistic character who just dies and leaves it all to you or runs you around the game showing you where to go.