Evil route in Baldur's Gate 3: Do evil things for sake of evil. Who is doing evil things that don't give him anything? Is there a reason for him to do evil things?
Ransacking the druid grove gives you tons of stuff and is easy to solo.
But yea, Minthara needs a more proper introduction and possibly a new path should be made from where we meet Lae'zel to the Goblins in the village that we can trick with our tadpole. Making both sides equally straightforward to run into and if we go straight to the goblin camp we are directed to Minthara who needs help finding her scouts and doesn't want to send out anymore of her own people.
Then you can go help the goblins kill the adventurers (who in this situation wouldn't be at the gates yet) that were with Halsin looking for Nightsong and bring back the goblins, earning their trust.
From there we have an actual starting narrative that is at least a bit more equivalent to the "good" side. I wish Larian would hire some more writers it really is needed to flesh out a game with so much choice in such a deep and established world. DM me