New Player Here - Need Help With Character Build

I love me a good skill tree and I love me a good class archetype system. As far as I can tell, most things are viable. I’m playing with 3 friends, and they’ve all got their niches figured out. My gf is going to be a melee warrior type character, we have a friend who’s gravitated towards using the wands, and my other friend is a Ranger. I tend to gravitate towards assassins or rogues in RPG games, but I’ve heard that daggers aren’t really viable. I’m not exactly sure what to build around anymore because of this, because I feel that it’s more fun and interesting if everyone has their own unique sort of playstyle.

So…I like dex and int characters usually that are focused on DPS. What are my options? Are wizards/staves any good/fun? Or should I just bite the bullet and do something similar to what my friends are doing?

I’m probably overthinking this, but character builds and skill trees are where most of the fun in RPGs and games like this are for me personally.