Sure I can explain her glyph's. Let me just post this and then edit it. And welcome to the 'dungeon!!!!!
Most of these exploration-based Castlevanias (dubbed "Metroidvanias" or "Castleroids" due to the similarities to the Metroid franchise) feature equippable weapons with a magic meter for special skills. For Order of Ecclesia (which fans call OoE for short), it does away with the usual system. Instead of equipping a sword, or an axe, or a dagger, or some other weapon Shanoa equips a magical spell (a.k.a. the glyph) instead. Attacking with any of her weapons drains her magic meter. When you attack until the meter runs out, she needs to rest and recover her magical power.
How do you get new glyphs? Some are straight up given to you. Others *might* drop off of an enemy. If you kill an enemy and they leave the distinct "SYNNNC" glyph noise and a blue (or red) swirl but nothing appears, they didn't drop their glyph. An example of this enemy would be the axe-knight and archer skeletons. If you kill them and they leave the glyph, just hold up and absorb it into Shanoa's back.
Some enemies you can absorb a glyph off of them while they are alive. An example of this is a necromancer type enemy who summons zombies. You'll notice the glyph pop up over his head while he's summoning a zombie. This is your cue to snatch it from him. Later on you'll find more enemies like this, like a green lazer skeleton and a floating goat using holy magic against you.
But wait why are some glyphs red and some blue? Blue glyphs are your basic equippable weapons. Red glyphs you toggle on and off with the shoulder buttons. Red glyphs can do anything from letting you summon allies (like the zombie glyph you swiped off of the necromancer) to raising stats, to even stuff like letting you regenerate health, pass through special walls, fly, or just run reeaaaallllyyyyy fast.
But wait I already got the same glyph more than once! If it's a glyph that summons allies, absorbing more and more of them will SLOWLY make them more effective, like summoning 3 zombies instead of 2. When you use those glyphs they'll show Level 1 (LV. 1) Level 2 (LV. 2) or Level 3 (LV. 3). Level-ups for these occur about every 15 copies you absorb.
What happens if you get the same blue glyph more than once? Nothing much. As you use certain types of weaponry over and over and over (like bladed weaponry, blunt-type weaponry, holy magic, fire magic, ice magic etc. etc.) you will notice numbers on the bottom right of your screen when you pause the game. These reflect Shanoa's overall expertise with a certain weapon, which will VERY VERY SLOWLY raise damage as you start getting up there. Killing enemies adds anywhere from 1-10 expertise to that type, while absorbing a glyph will raise all of your expertise points by 1. Since expertise points cap at 9999, you would have to absorb A LOT of glyphs to notice a difference. Red summoning glyphs also get stronger with kills, but it is FAR faster to level the summon glyphs up by absorbing them over and over.
Is there an expertise for stat boosting glyphs? Nope. Once you get it you've got it and it will stay the same.
You also asked about the weaponry. I'll explain this too. Despite the fact that Shanoa uses magic to make weapons, her stats still modify the damage. A sword, or rapier, or dagger, or hammer, or some other weapon that you would realistically need strength for uses your strength stat to calculate damage. If it's a more traditional spell like fire or ice, it uses your intelligence to calculate damage. Expertise also plays a role, but for the most part use strength boosting equipment for strength-based weaponry and intelligence raising equipment for intelligence-based weaponry. And some glyphs are just naturally stronger. Slower weapons like a sickle or a sword will always do more damage per hit than something fast like a dagger or a rapier. Of course if you sneak in 4 or 5 rapier hits for every sword swing you might do more with the faster weapons in the long run.
The enemy type also determines damage. Hmm that big nasty Hell-spawned demon just popped up. Chances are holy damage will hurt it more. That skeleton walking around will shrug off sword damage, but something like a hammer will hurt it more. When you press select and see either blue or red boxes next to the enemy, it means what damage types have a bonus (or penalty) against that creature. If the box is red, the damage is higher (and chances are the enemy will flicker red when you attack them). If the box is blue, the enemy is STRONG against that type of damage (and chances are they will flicker blue). What if there's no box for the damage type I'm using? In that case the damage isn't affected. What are those stars? I'll get to that.
What about your other stats? Defense is for PHYSICAL damage. CON (constitution) raises defense. MND (mind) is your defense against MAGICAL damage, including that nasty geyser of flame shooting from that trap. LCK (Luck) is your odds of getting things to drop, whether it's an item (remember those stars? The more stars next to an enemies' question marks the harder it is to get that to drop) or the chance of an enemy with a glyph that MIGHT drop on death dropping (like the axe-knight or the archer). Luck WILL NOT raise your chances of getting a glyph you have to absorb off an enemy while it's still alive, like that necromancer or that flying goat bastard.
Hope this helped!