the first Magic-User your PCs will fight? Probably a goblin shaman,
right? Maybe a bandit spellcaster I guess, but something like an orc
or ghost or elf is a bit too powerful and high fantasy for the level
they're at, wouldn't you agree?
Well I don't think that goblins should cast the same spell as people should. That's dumb. What kind of goblin knows Sleep or Magic Missile? They don't. They're fucking goblins. If your PCs run into a shitty low level goblin spellcaster; roll 1d8 on this table to determine their spell.
8 Goblin Shaman Spells Repulse - 1st level
This spell is the opposite of Charm. It works much the same way though. The shaman casts this spell on themselves and become instantly offensive to the eyes, ears, and noses of everyone around. Their voice seems shrill and annoying, their face becomes ugly and warts highlighted, and their smell is amplified to noxious levels. Goblin shamans often wear masks or hoods to hide their face before they cast their spell, revealing its effects with a dramatic flair.
Essentially, this spell works like Charm in the sense that nobody wants to mug you afterwards, but it's not because they think they're your friend but instead because nobody wants to get near you. Hirelings must make a morale check to attack (with melee) or loot the shaman.
 Enflamed Mucus - 1st levelGoblin version of a weak offensive spell. Uniquely, it can be used in a grapple. There's no incantation or somatic components- you just sneeze. Your snot comes out in a larger then normal mass with an incredible heat, like burning oil. It can light flammable things on fire, usually the ends of torches or wads of cloth goblins may use as projectiles on occasion. Also, goblin fire arrows.
If you're grappling a shaman and they cast this; you must save or drop them from the surprise of getting snotted on with fire. Deals 1d2 damage, or however much the burning object would do.
 Flying Shadow - 1st levelThis is a weak curse cast by goblins, and one of the only reasons they are feared. When cast, this spell creates a flying shadow that flies towards the target's face. If the target succeeds a save, their vision is darkened as though everything around them is dark and shadowy, but they can still dimly see. They get -2 to hit with melee attacks and -4 to hit with ranged. If the target fails the their save, they are blinded for 1d2 exploration turns until their vision returns.
 Maggotmail - 1st levelThis is a defensive spell shamans can cast on themselves or on their warriors. It has a range of about a stones throw. When cast, a swarm of maggots will appear either out of a nearby pile of trash or underneath the target's clothing and bite each other- they hang on to the target and form a suit of armor made of their squishy bodies.
The target of this spell gains +4 AC until they are hit three times (maggots are all squished) or they are hit with a torch or other source of fire damage (the fire scares away the maggots). It takes one round for the armor to form when this spell is cast, so it may be possible to kill the target of the spell before the maggots create their barrier. In which case, the maggots just start eating the corpse instead.
 Ice Touch - 1st levelThe most powerful offensive spell known to the average shaman. This spell requires a melee attack. The goblin touches you with a hand as cold as ice. The victim takes 1d6+1 damage as the cold rushes through their body. If you are killed by this spell your corpse falls to the ground very cold and still- this spell actually creates corpses very suitable for raising the undead and was probably stolen from necromancers by the goblins.
 Acid Piss - 1st levelThis spell grants the shaman a full bladder of pissy acid to pee out. Unlike the name, the “acid” isn't really very dangerous to living things and can't be used as an attack, it's a slow acting thing more effective against the inanimate. The goblin can use this spell akin to a Wizard's mark, but instead, they pee a frowny face on the dungeon's bricks somewhere and it gets burned on. Can also be used to escape from ropes or cages- they just pee on the lock. Obviously, this spell is a little more useful for boy goblins then girl goblins.
 Count - 1st levelGoblins aren't good with math. This spell helps with that. Instantly counts a large number of similarly sized objects that the goblin can see, or does basic math on something you can see or sense. The spell's result is returned inside the goblin's mind- meaning it can be cast in stealth. For example, a goblin shaman could cast this on a camp of sleeping adventurers to see how many there are, since he's not smart enough to count the boots and divide by two (but it still won't count the Rogue that snuck up behind him on his watch). Also commonly used by goblins to see how much treasure is going to be stolen from them by bigger, meaner monsters.
 Bravado - 1st levelGoblins are cowardly creatures. This spell helps with that, and is a staple in any large scale goblin attack. The shaman must use a drum to cast this spell, which works best if made of human skin. The drum is banged as a goblin howl is echoed- the goblins are inspired to fight and put aside their cowardice for but a moment. All goblins who can hear the song gain +1 morale.