I like to play my RPG games in real time which means no save scumming. I have absolutely no doubt that I can beat the Kobolds hunters when I know exactly what they are where they are what they can do and what their weaknesses are.
Lots of people go into these fights blind and do them first time, myself included. It is not difficult as long as you use the mechanics the game gives you. But I get the impression you desperately want DnD or BG3 to be like Diablo. Rush in, spam abilities, get loot.
For example the suggestion to engage the Kobolds at point blank range .... It would work great if I actually had someone in my party that could hit with a devastating number of hit points.. none of them can.
Gnolls, not kobolds. You meet kobolds later on. Level 2 to level 3 is a bit early for absurd nova damage. Still, by this point in the game you already have some magic weapons e.g. the everburn blade. A paladin using holy smite or a fighter using action surge can outright kill a gnoll in a single turn. If you already have Withers you could respec Shadowheart into a tempest cleric giving you several early game very strong aoe options... and so on. Trust me on this, you are not lacking damage options, far from it.
Pretty much every spell in the game to the point I played are incredibly weak sometimes hitting for only one or two hit points. The ones that have higher pit points are all very difficult to use and often miss.
Yeah, the game is based around dice rolls. There will always be an element of randomness to these fights. If you want to hit more reliably use stuff that can not miss, like magic missle, and try to get advantage e.g. by having the higher ground. Later on you say you are playing a mage, cantrips are weak, they are not meant to deal much damage. Did consider bringing some scrolls? There is an absurd amount of scrolls in this game.
The take-home message is I don't feel empowered playing this game ... And I get more than enough disempowerment in real life why would I pay for that?
The problem is, you have to realize several things. First of all, not every game is made for every player. I love soulslikes, so difficulty is not an issue for me, nor is dying and learning from my mistakes. Every soulslike released gets the nasty discussion that it absolutely must have an easy mode, because people are entitled to play it, no matter their skill. So maybe BG3 with its randomness, dice rolls, uphill battles, skill needed in creating viable builds, managing a multitude of combat options simply is not your style?
The second thing is, I kinda have the feeling you are not willing to invest the time needed, to play this game good. When I started, I haden't played a proper cRPG for ages and my first steps felt frustratingly difficult. Enemies mopped the floor with my character minutes after leaving the Nautilod. Now I'm complaining that the game is way to easy on tactician, as I steamroll every encounter. I still lose from time to time, but I don't mind, repeat and learn. Do I have better gear? Nope. Did I install easy mods? Also nope. But I did get into the mechanics of the game and learned to create powerful characters and get to a point, that even unkown encounters are an easy win 90% of the time.
The best suggestion for you still is, take it slowly, take the time to learn and don't get frustrated. The power curve of this game is in your favor, level 5 is a major growth in power, just keep going. And if you feel everything is to difficult, you could still use story mod and crank up the difficulty once you are more familiar with the game.
Some might say I chose the wrong party and the wrong playing class as It seems being a mage is seriously underpowered.. but I would rather fail at the game then complete it with characters I hate and that eliminated two right off the bat.
Well, mages have a rough start, always had in DnD. But you still have the option to go in with 2 fighters, it is absolutely possible to recruite Karlach and Jae'zel without having to fight a single gnoll.
