In the early game, before level 50, focus on training sets or apply gear as you get it from enemy drops and quest rewards. If you are trying to level a new character quickly, you can either craft a set with the training trait on all the pieces or ask someone to craft one for you. These training sets will increase your experience gained from kills, and typically are worn for 20 levels before being replaced. The reason for this is that as you level, the armor and enchantments on gear will provide less benefit the higher above the gear level you go.
For instance, if you get a training set crafted at level 6, it will provide good armor and enchantments to start out, but as you level the armor and enchantment values will go down. Alternately, you can just equip armor and weapons as you get them, from dungeons, level rewards, chests and quest rewards, and these pieces will always be leveled to whatever level you are at the time. This is a good way to keep updated armor until you are ready to farm for gear.
Gear levels are capped at CP 160, meaning any gear you pick up above that level will always be CP 160. This is the point where you want to start looking for early end game content gear sets.
Alternatively, all of the Overland Sets can be bought on guild traders, in case you are not up to farming them. If you have any doubts about how to use guild traders you can check our Guild Store and Traders guide