In the current NA/EU version of the game, your journey doesn't officially begin until level 10, thanks to a new patch that was added earlier on the tier prelude. The game starts off with some long(ish) cutscenes, of course you can choose to just skip it.

Next you just have to follow The Story Quest to start your leveling block. And these will be marked orange on the map.

From the current situation, we don't fully understand the experience rewards of various quests in the NA/EU version of the game. But in the Russia and Korea version of the game, you only need to complete the main quests to reach level 50, and no longer need to complete the side quests.

You also don't need to complete any quests other than the mainline quests, assuming that NA/EU will release the same patch in other versions. In addition, there are other ways to help you quickly upgrade:

You can sell some potions at the beginning of the game, you can use them for Triport (fast travel) to help you complete quests faster, and you don't need these potions during this time.

You should complete all mandatory Dungeons in Normal mode solo. You don't need to use any gear you've acquired during this time, as your gear will change all the time between 1-50.

If they overlap with your quests, you only need to complete the quests in the red areas, and this marker will show up on the map as you pass certain areas.

Get good at using Dash and mounts, they will help you a lot. While those tiers with strong AOE skills are good for quick content completion, you need to focus more on characters with additional movement skills.

To quickly level up your character, you only need to complete the main quests in the game, but if you want to quickly increase your character's strength, you need a lot of Lost Ark Gold. In https://www.mmowts.com/lost-ark-gold there are a lot of Lost Ark Gold for sale. They attract a large number of players to buy at a very favorable price. If you have a demand, you can try them, they will be very useful to you.