As a beginning player you will not be very powerful just because the level of your player and many other resources are needed to increase your cp. So it is a trap to only focus on leveling one character till it is super powerful i fell into it when i started the game during launch. But focusing on one character was okay at the time as their wasnt much family content. Now with soo much family content that can increase your and your family cp you need to spread your focus as a new player.

Number one is dont worry about finishing the story immediately do enough till you open up the map and then find a good place to farm that is matched to your cp.

Dont do boss rushes until you finish the story or atleast have hadum unlocked.

Boss rush is one of the most important contents in the game.

Create your main and get him as high as level 50 now do the same with 5 other characters. As a new player you will have a bonus to growth to a certain level dont hit that level and it will stay there. To pick which 5 classes you want to level up look up a guide to the best POG classes. Everyone has their own favorites but with the class balance changing recently there are alot of good ones. 

There are alot of things that are cool and will draw you to focus on them but are not important early as you dont have enough reasources to use them well such as.

-Getting the best armor and enhancing them as high as you can.

The problem with that is silver is drained when enhancing and you may need that for other things in the game at the start.

-Getting a cool outfit for your character.

The problem is if you find out you dont like that character and want to change you lost those outfits and the resources you used to get them.

Important things to focus on after you have all your POG alts.

-Camp level(it takes time)

-Finish the story till haduum is unlocked as fast as possible

-Get your fam characters gear to TRI(easy) and your main character to PEN(easy if you have enuf resources. resto scrolls are most important thing in game at higher levels)

-Desert is super important for Al's frags to get red gear and many other good stuff 

The main thing to remember in this game is if you do not have the game open and are farming constantly you will be missing out on resources to get stronger. Black spirit mode is okay but you dont get as much as you would just faming regularly. 

So last tip is get LD player or Blue stacks put the game on and farm as much as you can.