In some locations, such as Ancient Forest, Far Eerie Grove, Elven Grove, the Marsh and the Sea, possibly others, there is a chance of finding a chest. Those vary by types and can be either opened by expending 20 energy, using a lockpick or unravelling a section of a shady area with a torch (the latter type has a description that differs from one of a chest, but is functionally the same). If I recall correctly, both lockpicks and torches can be bought in Shaliq Village, and lockpicks might be available in some cities at the market. They can contain all sorts of equipment and/or materials. 

My personal advice would be to go to Elven Grove and assault elven patrols once you are able to defeat them. They sometimes drop elven chain armor (a nice set of armor that also gives you a speed boost, which means an evasion bonus), and elven swords (extremely useful pieces of equipment since all of them give +1 to agility and deal 9 damage plus whatever enchantment they have if you are lucky enough). Those that don't have any enchantments can be sold at the market for a good sum of money.

Also, bandit camps at the Sea and the Marsh might be your primary source of good slaves, since every one of them has two hostages that can be of absolutely any race, including dragonkin which are arguably the best you can get. Those are level 10~14 (roughly) encounters though, so max out your agility and speed if you wish to survive those. You can even solo them if those stats are high enough, since none of the 10 to 12 foes you battle are able to hit you consistently that way.