I'm trying to find a way to locate a point from another point using intersect or raycasting. Do these functions only work on polys?

Say I have point @{0,0,0}
I want to look for the nearest point at relative direction {1,0,0}

What's the best way?

Depending on what you are looking for exactly, you can use either

https://www.sidefx.com/docs/houdini/vex/functions/nearpoint.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/nearpoints.html [www.sidefx.com]

since you are interested in points in specific direction you can also use more specialized point lookup functions

https://www.sidefx.com/docs/houdini/vex/functions/pccone.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/pcsegment.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/pcline.html [www.sidefx.com]