This does not sound at all normal. Have you ever injured that hand? If not, then I would guess
(because I have no way of knowing without seeing you play) that you have some serious dysfunctional tension. Are you sure you can't take a few lessons with a qualified teacher? It is worth the investment not to hurt yourself. Your hand should not hurt if you are playing properly. Pain is a signal that something is wrong and you are wise to listen to your body.
If you cannot possibly do that, perhaps if you post a picture or short video of your hand position when you play and some of the teachers here could possibly help.
When you play, are your middle knuckles pulled back past the plane of the back of your hand? That is the main way I can imagine pain in the palm where you describe.
Or.... you are holding your fingers in a curved shape with too much tension.
Or....you are spreading your fingers wider than you ever have in your entire life (hard to believe, but it could be true...)
Or... you are holding your fingers apart with too much tension.
Are you playing ima on adjacent strings?
Do you have the pain if you are alternating im on the same string?
What exactly are you "practicing"? Not everything in Pumping Nylon is intended for beginners.
1 hour /day is a lot of time for someone just starting and 30 minutes is a long practice session in the beginning if you are having physical difficulties because you lack flexibility.
When the sun shines, bask.
Classical Guitar forever!