I would address this in three phases: before, during, and after.
Before, only if this is an expected transit, would be either fear or anticipation.
During, if this is a simple portal, would be near instantaneous and would be described by simple feelings: nausea, falling, heat, cold, pressure, bright light, darkness, etc. If it is an extended transit, something like a tunnel rather than a portal, then one could have a more magical feel. I think this would largely be what the PoV sees rather than feels: flashing lights, mystical creatures, three headed dogs, other travelers, etc.
After, primarily if this is the first visit, would describe the destination with all senses in play. If the PoV has been there before, then it is a little more difficult to provide the description; perhaps focus on something that has changed since the last visit.