Yes, it would seem a little odd if you’re used to Northern European cathedrals.
You really need a guide book or the audio guide to go around it. I too baulked at having to pay, but I must admit that the audio guide is well worth the small fee and is in several languages. You get it at a desk just to the right inside the entrance. Don’t miss the recently uncovered renaissance ceiling frescoes by Italian artists, commissioned by one of the Borgias (a Valencian family who supplied a couple of Popes).
Also, if you’re there on a Thursday morning, you can see for a few minutes the Water Tribunal, which meets at 11 o’clock sharp that day outside the Apostles’ Door as it has done for OVER A THOUSAND YEARS. It hears complaints to do with the irrigation canals around Valencia that were started by the Arabs.
On the big square behind the cathedral, called the Plaza de la Virgen, there’s another large basilica with fine ceiling frescos.