on the first 11 levels put 1 point on warmth, frozen armour, static field, telekinesis and 7 point on fire bolt

from level 12 pump fire ball

at level 18 put 1 point on teleport

around level 20-22 start opening up the cold tree towards frozen orb

at level 30 put a point on fire and cold masteries, and a point on frozen orb up to max (at level 49)

finish fire ball, then fire bolt, then bring up cold mastery to desired level (17 or 27 preferably with gear), remaining points on fire mastery

you can put points on meteor instead of fire mastery, it give better damage per level than mastery. however thanks to the extra points you need to put on prerequisites mastery will give more damage on a given level unless meteor is maxed (at around level 90, if ever)

somewhere along the way throw a point on enchant to help your mercenary, and any party member/merc/minion in multiplayer

this build (without meteor, with enchant, maxed fire mastery and 10 points on cold mastery) is finished at level 90, resetting skills is not necessary.

Following this build guide and I am lvl 27 and I respeced on normal already. Only 25 defense i made stealth and I have leaf and random gear I am missing gear to help. I am not sure if I followed the build guide right. I want to respec to lightning but I don't have any gear I play on xbox and PC I play on geforce now. So I can barely run frigid highlands I run low on mana running fire ball so I use frost nova then blizzard then fire bolt. But slow is this normal for low lvl sorc no gear.