I want to run a new 20A service and 2x POE lines from my basement to my garage. Can I put them in the same pieces of conduit or do I need two? Piece of conduit would be less than 1 foot in length.
There's a gizmo made for precisely this sort of job
While Exception 1 to NEC 800.133(A)(1)(c) or 800.133(A)(2) would permit the shared sleeve you describe, I would not bother with your conduit sleeve approach here to begin with as the fireblocking foam fill would create issues with potential cable damage during re-entry that could be quite troublesome. Instead, if you don't mind spending a bit of money on the problem to save you a lot of fuss with foam later, I would throw a made-for-purpose gadget at this job, the STI EZ-Path 22. These are available through various industrial and electrical suppliers for under $100 at the time of this writing, and provide an easy-to-install, easy-to-reenter, and proven safe (the device I describe is UL and FM approved for full-blown penetration firestopping in places like hospitals and high-rises where that stuff matters) solution to the problem.