Your combat training and your experiments with magic have paid off in two ways.
Arcane Empowerment
When you attack with a magic weapon, you can use your Intelligence modifier, instead of your Strength or Dexterity modifier, for the attack and damage rolls.
Weapon Knowledge
You gain proficiency with Martial weapons. You can use a weapon with which you have proficiency as a Spellcasting Focus for your Artificer spells.