You're a pyromancer

Pyro Savant

Beginning when you select this school at 2nd level, the gold and time you must spend to copy a fire spell into your spellbook is reduced to 1/10 the cost.

Pyro Sculpting

Beginning at 2nd level, you can make any number of creatures who would be affected by your fire spells immune to them by weaving the flames of the spell around them harmlessly.

You may also change the damage type of any spell you cast to fire a number of times per long rest equal to 1 plus your proficiency bonus. If the spell is a concentration spell you need only spend one charge of this ability to change the damage of the spell for it's duration. 

Explosive spells

Starting at 6th level, your fire spells have a chance to cause a small explosion on impact. If you roll a 19 or 20 on a d20 roll to hit an enemy with a fire spell it gains a radius of 5ft, damaging each other creature within the radius for half damage (no ac check or save).

Additionally, your fire spells always make little cracking sounds on impact that are very distracting. Creatures dealt damage by your fire spells have disadvantage on concentration saving throws against those spells. 

Searing Flames

Beginning at 10th level, you can increase the heat of your fire spells to deal additional damage. You may add your intelligence modifier plus your proficiency modifier to one damage roll of a fire spell that you have cast.

Concussive Blast

Whenever a creature takes a large amount of fire damage from a spell you cast, the shock-waves of the explosion send them reeling.
An enemy who has taken 25 or more fire damage in a single hit from a fire spell you cast is knocked prone and is dazed giving them disadvantage on their next roll with a d20.