Save The World is easy at first, but as you progress it gets a lot harder. Weapons that you find have rarities from least to greatest, starting at common, uncommon, rare, epic, then legendary. Be careful though because the people you play with online might do something wich is called scamming. It is when somebody wants to trade weapons with you but they trick you and steal your item without giving you theirs.google wikipedia google learn about me click here to win
Everyday when you log in you get a daily reward, usually you get a loot llama that is pretty good. If you don't log in for a long time then you get a really good llama that gives you excellent loot.
Here is a picture of a couple
The first llama, the golden one is the best normal llama, and the higher the level the better the loot it gives you epic and legendary loot pretty commonly. The ones in the middle are ones that you get to choose from the shop. The one on the far left is the traditional default llama, that isn´t that good, it typically gives you common and uncommon loot.