When you're leveling you really need Health. Having some points put into magicka is good too, but health needs to be your focus so you can take a few hits.

You should also not just be relying on your class abilities. At low levels your weapon attacks should be your main source of damage. As your magicka pool is so small you should be using it for utility. The one exception is Mage's Fury from storm calling which you want to execute enemies once they are at 20% health or below.

From dark magic, consider encase to stop melee from getting too close. Storm calling Mage's fury (as above) and perhaps lightning form to increase your armour and spell resistance.

Also consider getting a summon to help level your Daedric Summoning tree. Remember there is a command you can use to tell your summons to attack a target without you needing to attack first. This means you can have them tank a target while you stand back and DPS. Daedric Summoning also provides some important survivability skills for sorcs at higher levels.

Are you leveling any crafts? I'd recommend at least researching 3 traits on a few light armour pieces to allow you to create your own crafted set of gear. Namely the Seducer's set. Check the link below for set crating locations, but remember you need to have researched enough traits for a armour piece to make it.

http://http://elderscrollsonline.wiki.fextralife.com/Set+Bonus+Crafting+Locations

The key thing at low levels, especially if it is your first run, is to try everything. Running heavy armor on a sorc at low level isn't necessarily a bad thing. Keeping a skill you don't use on your action bar can be good as it helps you level the line anyway (as long as you have that extra room for it). Experiment, don't worry about messing up because once you hit the Veteran Ranks I guarentee you will respec all of it anyway.

There are shrines in your faction capital (Elden Root, Wayrest, Mournhold) that allow you to reset your skills and stats for a cost per point. So the more points you've allocated the more it will cost to reset.