So I'm just going to say the current fastest way is this here. Everything everyone else has told you about fast cp lvling from a fresh start is outdated since season characters started.
1. Create a 'Season Character' and 'Auto Story' to 4k cp
2. Go to West Valencia and farm Tuvala items and Scrolls until you get to 10k
3. Go to Resonating Beach Chaos Zone in North Calpheon to farm for the rest of your upgrade materials once a day, glowing purple map marker.
4. Auto story while you are not at the beach.
5. Craft some Vials of Light after saving up some Lightstones and then farm Hadum in Valencia for Advanced EXP Scrolls(they are red and black and give 15,000,000 EXP).
6. Upgrade your Tuvala Weapons and Armor to +20 first, then Accessories +10, then Relics +10, Lucky Stone +40 then +10 more times to X, then finally the Totem +10. Do the upgrades in that order since it goes easiest to hardest.
6.1 Once fully Upgraded and all quests are complete you have two options. Don't craft the Ah'krad Crystal until between the 8th-10th of December, you can go to the beach daily to collect valks, akhram, and insane money. You can't do this if you graduate.
6.2 OR Once fully Upgraded, Craft the Crystal, Graduate, and Proceed to unlock the Gear Copy ability though the Chaos Accessory Questline.
7. Leftover Tuvala Ore can be Crafted into the other Tuvala upgrade materials if you have the blacksmith unlocked at your camp.
7.1 Leftover Tuvala Accessories can be broken back down into Tuvala Ore to be crafted into Tuvala Lucky Stones to be sold at 100,000 Silver a Piece, this is the most you will make off of a Tuvala item.
8. Buy the Season Pass, it's only $20 and gets you a lot of really good stuff to help you advance faster, it is more than worth the $20 value.
9. Do Repeatable Quests, Boss Rush, Ayelli's Realm, Ancient Ruins, Constellation, Pirates Beach, Valor Hadum, Tower, and all the other modes as often as possible. Building your Knowledge of enemies and bosses will get you insane amounts of cp and will often get you past those pesky cp walls you will enevitably run into as a new, or even experienced, player.
9.1 Know how and where to get more passes.
10. ONLY SELL JUNK, the junk items have a litte grey bag icon on their picture. If you play the game correctly you will never need to sell anything else.
11. Feed Relics at the same level or lower to the ones you have currently equiped to each character in your family to the ancient relic tower. Each blessing needs to be at its max lvl of 100 to unock the 4th blessing that raises all branch damage. There is an auto feed option in the fuse relic shard page in the coin shop. There is also an advanced shop option that grants only orange and red grade but you will need 1000 fragments per rather than 10 per.
11.1 Lightstones have a similar setup. Only use old lightstones you don't plan on using for crafting Vials of Light. Also Primal Lightstones, and above, can he enhanced to +20 if you get lucky.
12. If you aren't going to use old armor for upgrades or enhancement transfers feed it to the black spirit. In fact expiriment feeding it different stuff, it geves you a breakdown of the items you recieve between the item selection page and the offered items list before even feeding him.
12.1 After a certain point you will earn a lot of Shakatu's Gold Coins. Save up close to 50million+ and use his tier 3 exchange on the main weapon, auto feed everything to the black spirit, except red gear if you need it.
12.2 You can also use Shakatu and Hadum tier 3 blessing in Valencia to instantly jump start entirely fresh non season characters right up to 25k cp easy once you have the right materials and currency to do it. As reference I made a 25k lvl 80 Choryeong in less than 4 hours and I've done it with 13 other classes, and counting.
There is a lot more but I will save that for Guild members.
If you have more questions, are on the American Server, and need or want a guild please feel free to come Join Norinomu - Zefos - Guild Master