Pure Mage
A- Magic
B- attributes ( you should have max tradition attribute, soft max willpower, 3 or 5 body, 4 or 5 intuition)
C- meta ( 5 - 7 edge)
D- resources ( power foci 3, 4 or 5)
E- Skills
you may switch B and C depending if you choose elf. Edge does very nice things for mages.
You want at least power 3 or 4 at character creation, it makes a huge difference.
Focus concentration is also excellent for a pure mage build
A - Skills is a terrible idea, and should never be done, if your goal is pure mage.
B- Skills is also a terrible idea if you goal is to make a pure mage.
Seriously if you are only using 5 Spells, you are not doing something right.
At the very minimum you should have
indirect single target spells
AOE indirect spell
Combat sense
increase reflexes
improved invisibility
Levitate
heal
Incredibly useful spells that can be used almost every session : control thoughts, mind probe, trid phanstasm, physical mask, shape metal
incredibly powerful spells in certain situations : mana static, turn to goo, alter memory, detect ( life, enemies,) analyze device, fix
nice addition spells : fashion, sterilize, chaotic world,
And you don't need a gun. it's usually a terrible waste, because agility in one of the lower priority attributes, and honestly that's what the street sam is for. As mage you generally have better options anyway than firing a gun.