If you're going to go a spellcaster you have the choices of Sorcery or Pyromancy.
Sorcery scales mostly with stats. Pyromancy scales entirely with an upgraded item called a Pyromancer's flame. Sorcery has a diverse amount of spells. Pyromancy is almost entirely fire damage.
Stats for a sorcerer are mostly going to be intelligence for scaling, attunement which allows you to equip more spells, and vitality which increase your health.
Strength and Dexterity will play their part when you pick your weapon, and you will need a weapon. Endurance increases your stamina and how much your equipment can weigh so it has its uses but as a sorcerer your armor is typically going to be very light.
Faith lets you use miracles which you wont want as a sorcerer. Resistance is literally a useless stat.
For stats you want to start off by going for the soft caps.
Vitality is 30. Intelligence is 40. Attunement is 50. Soft caps are where more points invested will result in you getting less of that stat for each point.