The shop in the League of Legends client uses various ingame currencies. As a beginner it is easy to lose track of what they are all used for. Here you will find an overview of the most important currencies in the LoL client:
Blue Essence (BE)
Blue essences are substantial, because you need them to unlock champions. The costs for the champions are graded according to the age of the champ, and range from 450BE (old champions) to 6300BE (new champions). The price of champions can change downwards, because with new releases of champions others are permanently reduced in price.
In addition to champions, you can also buy cosmetic items and eternals for blue essences. What is important for all players, however, are the rune pages: Since you only have two rune pages at the beginning, changing the runes can quickly become annoying. In the shop you can buy rune pages under Accessories for 6300BE.
You get blue essences for the first victory of the day (50BE), through level ups or through the associated champion capsules that drop champion shards. The champion shards can either be upgraded directly to the champion, or they can be disenchanted for some BE. The amount of BE that you receive for disenchanting depends on the current price in the shop for the champion.
Riot Points (RP)
For Riot Points you get all kinds of cosmetic items: skins, wards, chromas, emotes, but also icons and champions. Rune pages can also be purchased for RP. There are also various bundles when it's time for events again.
However, RP can only be purchased with real money. There is no single way to earn it for free. That makes them valuable and you should use them only on meaningful things. All items in the shop that can also be bought with BE should therefore also be bought with BE.
This currency is used in the Hextech Crafting and is of great importance for many, because it can be used to craft skins without having to spend money.
The free loot box, which is activated for your account every week, allows shards to drop for champions, skins, wards, icons and so on. These shards can either be upgraded to the full version of the item or disenchanted. You will receive orange essences for disenchanting skin shards, ward shards, and eternal sets.
With the orange essence you can now upgrade other skin shards and add them to your inventory (forever!). The amount of orange essence you get for disenchanting is again based on the price in the shop.
These purple gems are extremely rare (3,6% drop chance) and can be found in hextech chests. From level 150 you also get a gemstone for every 50 levels.
Ten collected Gemstones can be redeemed for one of the hextech skins. At the moment there are 18 hextech skins to choose from and new ones are often being added. These skins are very valuable because they are extremely rare. For just five Gemstones you can unlock the hextech ward, which you can use instead of the default ward skin.