I was in similar boat as OP, and yeah learnt its all about shields otherwise you get smashed. Still do to be fair with bar swapping and timing complexity.

For a Magicka Sorc, dump any Champion Points you have into Bastion to improve your shield. If you don't have any CP, that's something to worry about later.

Protection in PVP can come from (in no particular order):

Armor - though if you're a Magicka build, you should be using light armor which is not much protection, so a lot of people use one or two pieces of heavy on their largest body sections (Head, Chest, Legs) to get some extra protection without losing the magicka passives from light armor

Light Armor Skill - protects against Magicka (though it also offers protection against things like flames and poisons and such)

Medium Armor Skill - simply makes ~20% of attacks miss you, but costs substantial stamina

Heavy Armor Skill - gives a huge armor buff, but costs substantial stamina

Hardened Ward [morph of Daedric Summoning-Conjured Ward] (never let it drop) - protects against all attacks

Streak (morph of Storm Calling-Bolt Escape) - If you are getting pounded, this moves you away and stuns (and damages) those in your wake. With a lot of Magicka, you can just Streak away until you can hide.

Defensive Rune (morph of Dark Magic-Rune Prison) - this is a life saver against annoying NB surprise attacks or those people who like to use macros. It stops the attack sequence in its tracks and gives you a moment or two before they break free to regroup. It also lasts a full minute after casting, though needs to be recast once triggered.

Bound Aegis (morph of Daedric Summoning-Bound Armor) - gives a nice boost to your physical and spell resistance and increases your max magicka, which makes your Hardened Ward stronger

Restraining Prison (morph of Dark Magic-Encase) - this Crowd Control (CC) ability stops opponents in their tracks and leaves them slowed for a few seconds after

Defensive Stance (morph of Sword & Shield-Defensive Posture) - this buff is nice because it lasts 30 seconds after casting, but only reflects one magic projectile and then needs to be recast. It costs stamina, but its not a huge amount

Learning to Block Power attacks and crap like the ever-abused Wrecking Blow will help a lot too as not only do you take a lot less damage, but you don't end up on your arse. Good blocking is an art all in itself.

Daedric Minefield (morph of Dark Magic-Daedric Mines) - this is great defensive spell as it drops a field of very damaging mines that also CC the opponent. And this leads to the next thing ...

Use terrain as well. Get out of line of sight, Streak somewhere and go around a corner. I see a lot of Sorcs get into a small crack between rocks and drop Daedric Mines and while their opponent is stuck, they pound them or heal or whatever. Speaking of heals:

Healing Ward (morph of Restoration Staff-Steadfast Ward) - gives a big damage shield that heals you a lot when it drops.

You're going to have to try different things out and mix and match and see what works for you. If you're wanting to be offensive, then the Wards may be all you need. When you want to be Defensive, maybe a Ward with the Daedric Mines and something else. Maybe set up the add-on Dressing Room and flip between builds (when not in combat).

I actually run a very strong Magicka Sorc Tank in PvE who is able to get through any dungeon situation I've come across, but his DPS is crap, so in PvE, it would be of limited use. Also be aware of Shield Breaker sets when you get to the Vet PvP. It sucks for Ward users.

Good Luck.

Seems like you're on the right track. CP in Bastion is also a good call. Persevere with it. Mag Sorc is in a good place for sure.

@RobbaYaga nah all my attributes are in magicka tho and I have the Mage mundus stone