There are a lot of way to support the party attackers with low level spells or even cantrips : for exemple using "heat metal" on clasps, buttons, rivets, necklaces, bracelet, rings, earpieces and other jevellery, coins, metallic armor elements close to the skin or a badly maintained weapon used by an opponent is a really effective distraction, especially in the middle of a battle.
For water, a simple water ball of a few dozen of centimeters fixed (just like magic light can be fixed on a person or an object) on the head or the nose and the mouth of an ennemi can be deadly.
A simple wind spell could really do marvel against long ranged arrow fire or help your archer comrade.
If the mage can be stealthy simple telekinesis, mage hand, invisible servant and ventriloquy can start an in-fight in an enemy group especially with thoses with brawny alphas and such.
I could go for hours about grease, one of the most powerfull spell to ruin the day of any enemy (and it's also really usefull defensively)...
Each time I played a mage or an illusionist in a tabletop RPG I made sure to use smartly low level spells to screw over any kind of monster and opponent or to provide all sort of advantages and opportunities to the frontliners, after all many battles are won before they start...