Crowd control is inherently limited in Underrail due to its utility, generally by cooldowns.
You might be able to do quite well on lower difficulties focussing purely on crowd control, but I find it hard to recommend a pure indirect damage CC-focussed build to a newbie because they are generally meme builds that could easily end up being frustrating.
That includes traps, because the time taken to set them up before every fight can end up being quite a drag.
That being said, if you want CC, the obvious choices for skills are Throwing, Traps, Thought Control, Metathermics and Psychokinesis.
Melee weapons can also be used to proc many CC effects like stun, incapacitation, daze, fear and tackled, so combat gloves and bare fists are also excellent direct means of applying crowd controlling effects due to the number of times they can hit per turn.
Chemical pistols, as mentioned in the post above mine, are also excellent for the variety of effects they can inflict on enemies.
The use of the Versatility feat is deserving of mention too, because if you want high throwing skill for CC, then you need high dexterity.
High dexterity can be used in conjunction with Versatility to make a character proficient in firearms use, and is most effective when using pistols and SMGs.
If you really want to give a CC build a go as a newbie, I'd suggest going for high dex and throwing, traps and psi too if you want and then branching out into other skills later if you feel like the build is lacking.
