Before I delve into this subject about proper character building let me share a story about what happened in BG today. So a person named Midgar who was a level 39 VIP with full clothes and wings had only around 4,300 or so PATK and was an archer with about 14k BR average. Now at that level I would not only have higher BR, but way way higher physical attack. This goes to show that people level too fast and some people like Midgar get way too cocky in BGs or group arena thinking they're the best and they can kill everyone. This isn't true at all.
Since, this game is about being patient and taking your time doing certain things. Taking things the slower route will pay off eventually, people generally just don't like to do harder things and stray to the easy path. Okay, so lets show the stats of level one wings.
PATK +120
MATK +120
PDEF +120
Max HP +1200
PATK +2%
MATK +2%
PDEF +2%
MDEF +2%
Max HP +2%
Now, since Midgar called me a 'noob' because I called him/her out on their character building I can see that without the wings s/he would have about 4,100 or so PATK, but they also mentioned that they had red astrals 'apparently' and that doesn't make them a 'noob' or anything. While red astrals are powerful, yes, but unless you level them up and have a decent combination of them then theres no real point about bragging about that you have red astrals, really.
However, let us get into the character building part. Depending what your class is you may have to have to deal with the fact that there will always be someone better than you in your class and generally, so if you feel bad about losing alot then don't let it get you down. Mages need MATK mainly for their attack stat, while Knights and Archers need PATK, so what that means is that one more class outweighs the other in terms of what damage is being used this is quite important to know and you will have to use that sort of mentality to see what you can do to defend against it.
It doesn't matter which class you are, you will always need PDEF and MDEF you can get these simply by getting guild skill, upgrading your tech to get the opposite attack stat you use, and astrals. This is why you tend to see alot of higher level players have a decent amount of another attack stat its because it can be used to boost their defense of that type. Such as PATK giving more PDEF and MATK for MDEF. Normally its a sterotypical thing to say that a Knight has low MDEF, this isn't always true at all. Again if you build a proper character you can defend against both with not as much as an issue as you thought, but it all depends how patient and dedicated you are.
As for Critical I find it very good for World Bosses mainly, but not too much for PvP or PvE unless I have a Determination astral which boosts crit damage in a percentage. Block is normally used by Knights, but anyone can use it and it acts as an extra defense of sorts, it can lower the amount of damage done to you and it may be something to think about later on at way higher levels, but don't worry about it early, early on. Some of the top Wartune players on Armor Games have used the block astral, but then again they were high leveled with really decent BR.
As for Charisma I tend to usually train this with guild skills at the very end, because Charisma mainly gives you more Troop Count and most people don't really bother with it anyways, however don't get me wrong it is still useful in its own ways. I feel that its not really worth it to even use Charisma increasing gems because either way your bodyguards will most likely get killed off anyways I tend to think of them as meatshields really, but later on they become fairly useful. Such as the Gryphon stun, Angels heal, and the Knights charge, of course there are also Templars and Warlocks. Plus, you would be better off using gems that would give you more defense or attack if you're feeling confident in your choice (you can always unsocket the gem anyways).
Most people use HP gems because they feel like they don't have enough, however if they don't have the proper defense stats to back it up then they'll find that HP fairly useless, if you feel like you have decent defense stats and think it can be alright to use HP gems, but otherwise don't even bother unless you can back it up.
My suggestion is to find a guild with a decent skill tower and guild shop so you can start leveling your guild skills and buy potions/upgrade stones for enchanting equipment. If you're a Mage focus on Intellect, Defense, and Endurance and if you're a Knight/Archer focus on Power, Defense, and Endurance. When you finish leveling your needed guild skills come back to finish off Gold, Charisma, and whatever else is left. You can start on astrals beginning at level 20, but I wouldn't focus all of your attention to them and always be sure to level your tech to your max character level, however this doesn't mean you shouldn't work on them from time to time, because they are fairly helpful.
But thats all for now and I hope you've found this helpful and informative. Good luck with character building and show Midgar whos boss!