Bought the game recently on sale while my gaming PC is in the shop. It's been pretty good, it's been a while since I played Baldur's Gate 1 and 2, but mostly remembering how things work.

Learning wizard spells does not appear to work in this version. Right-clicking a spell scroll in inventory doesn't bring up a description of the spell (or do anything). Only if you first put the scroll in a quick use slot, close the inventory screen, and then right-click on the scroll does the description come up. And then there is no button or option to learn/copy/write the spell.

I started off with the pre-created party and the wizard is a generic "mage" of chaotic neutral alignment. There shouldn't be any restrictions on learning any spells with this one, correct? I mean, she can't learn anything at all. Same with the bard.

I guess if this is a bug, the only thing to do is start over and make a sorcerer instead of a mage. Honestly, I forgot how terrible mages are in the early game, I basically just tell the mage to go stand in the corner while everyone else fights.

I opened a game in Icewind Dale: Enhanced Edition v2.5.17.0 (the latest available 32-bit version for Windows). I confirm that when you right-click a scroll in a quickslot from the main UI, you do not get the option to Write Magic, even when the character is a mage. When I right-click a scroll while in the Inventory UI, regardless of whether that scroll is in the backpack or in a quickslot, my mage is offered the option to Write Magic. I suspect then that your problem is that "(or do anything)" means that while you may be trying to right-click, the game is not recognizing it as such. If the game recognized the right click while in the Inventory UI, you ought to get some reaction, even if it is only the same dialog offered for the quickslot. Even non-mage characters can right-click an Inventory scroll to bring up a description of the spell, though as a non-mage they cannot Write Magic.

I am not aware of any spell scroll restrictions for a non-specialist mage.