Order's Wrath (crafted set) is one of the best beginner sets to use while farming for dungeon/trial gear, granting bonus to crit damage and crit healing.
Tideborn (I think it's called this and iirc is another crafted set) is another very strong set to run as well, granting a flat 12% bonus to direct damage done.
These 2 sets can be ran together as well while farming for other gear.

If you have antiquities unlocked, the Mora's Whispers Mythic is a nice generic starting point, granting a lot of crit chance based on the number of Shalidor's Library books read (eidetic memory books or lore books that glow gold instead of purple).

With this, there's 3 options here for the final gear piece:
1 piece monster set that grants crit chance (more damage)
1 piece monster set that grants max stam/mag or mag/stam recoveries (more sustain)
1 piece trainee set that grants max health (less damage more health to not die)

If you find yourself running out of resources, swapping the slotted health champion perk for the recovery one (both are in the red tree) will help with this as there are much better (and easier) ways to get health than giving up a champion point slot for it.

The other way to boost recovery is to use a relevant food buff. Witchmothers Potent Brew (I think this is the name) grants max health, max mag and mag recovery, buffing your health (more than the champion point does), while also buffing damage and sustain via more max mag and more mag recovery. There is a stamina version of this food as well if you are playing a stamina sorcerer.

Another way to help with sustain (if playing a mag-sorc) is to run 1 or 2 stamina abilities (typically damage over time abilities that don't have to be spammed so you don't drain your stamina to no longer be able to block or roll). Hurricane (stamina morph of lightning form) is one of sorcs best damage over time abilities (better than the mag morph) and also grants major resolve (armor buff) and minor expedition (speed buff). Barbed Trap (fighters guild skill) is another good option here too, providing +3% damage done (fighters guild passive) and minor force (+10% crit damage done) as well as damage over time.

Unfortunately when it comes to PvE, magicka Sorcerer (well the traditional mage playstyle using frags, lightning splash, fury, etc) just hasn't been updated to keep up with the games power creep (it's why so many sorcerers just run with a heavy attack build using pets instead).

Link:
https://en.uesp.net/wiki/Special:EsoBuildEditor

Build:


Notes:
Armor enchants are all max magicka
Jewelry enchants are all spell damage
Front bar staff enchant is shock damage
Back bar staff enchant is weapon damage
Attributes are 64 into max magicka
Slotted Champion Points/perks:
Red:
Rejuvination (+90 all 3 recoveries) help with sustain
Siphoning Spells (+1500 magicka restored if you land the killing blow on an enemy)
Slippery (optional/flex slot, auto break free once every 21 seconds)
Celerity (optional/flex slot, +10% movement speed)
Blue:
Master At Arms (+6% direct damage done, buffs everything except wall of fire)
Fighting Finesse (+8% crit damage and crit healing)
Deadly Aim (+6% single target damage done, buffs frags, armaments and the pets passive attacks)
Backstabber (+10% crit damage when attacking enemies from the back, this build doesn't reach crit cap without this slotted perk, still needs both major and minor force, but those should be provided by the group supports)
Note:
Backstabber perk is a flex slot if your character is a khajiit, since that race provides +12% crit damage and crit healing, my build had the race as high elf.

The reason for the medium pieces on the legs, head and feet and the heavy piece on the chest is that gives the best mix of survivability + damage via maxing out the undaunted max stats passive and enabling the armor passives for all 3 armor types. The only downside is not being able to use the light armor active ability, but that ability is extremely weak and needs a real update anyway. You can swap the feet and head for light armor pieces of the same sets if you want some additional magicka sustain, but this does slightly reduce damage.

The stamina morphs (hurricane and armaments) will also help with sustain since they are not spammed, but they do give a couple of cooldowns where you're not using magicka to cast something, giving your magicka pool a second or 2 to recover a little bit.

Rotation is simple:
Start with surge (damage buff)
Summon Atro here (if it's ready)
then hurricane (armor buff and long duration DoT)
then wall (shorter duration but procs the back bar glyph for damage buff)
swap to front bar
cast curse (buffs pet damage)
then cast frags unless armaments is at 4+ stacks or you need to recast any of the above abilities.

Optional to cast pets secondary abilities if you want more complexity in the rotation, start them before atro and only keep up familiar since the active of tormentor is not worth the wasted global cooldown on enemies below 60%.

Dawnbreaker is just passively slotted for the fighters guild passive that buffs weapon and spell damage, since that passive is slightly stronger per ability slotted than the sorcerer passive that does the same thing.

If you want some better cleave against trash packs and have access to scribing, I would recommend replacing frags with soul burst (shock damage) and just pre-cast surge + hurricane + familiar before the fight then spam soul burst. This won't deal as much damage against bosses since frags hits much harder and has the sorc passives, but will be better into trash packs where you just want to burn down as many enemies as possible at the same time.
If you don't have access to scribing, use Unstable wall in place of frags on the front bar (shock staff will make it shock damage on that bar) which will have a similar effect as soul burst but deals AoE burst damage when you recast the wall (causing the previous wall to explode) instead of on every cast.