Z was long-dead by 2007 but yeah it has graphics support.

You should probably try and come up with a different way to choose between variants since as far as I'm aware they pretty much all support graphics.

i tried Z today and i couldn't even cast a spell.

Check my profile. There are links to quite a few unofficial tilesets for variants.

i'm trying TOME2 now - being that i have tried 3 and 4 and they are weird and non-angband-ish. I'm trying to figure out HOW TO EVEN LEARN MY SPELLS.

V4 has just so much better of a UI.

You don't "learn" spells in TOME2 like in other variants, if you have the book and enough skill in that school you can cast the spells.

is it normal that a Lev 1 mage with 20 INT cannot cast any spells?

No. Have you put some skill points in the appropriate spell school (mana for manathrust, aka magic missile) (allocate skill points with capital "G", just in case you don't know that)?

Although if I start a human mage with 20 INT in Tome 2.3.5 I can cast manathrust with just the starting skill levels. Maybe the newer version starts with zero skill?

Mages start out with rank-1 skill in various magic realms, but which realms depends on the kind of mage. Hit 'G' to see what your skill ranks are, and therefore what books you can cast from. Only Sorcerers can cast from all realms, and they pay for that massive versatility with massive fragileness (each rank in Sorcery reduces max HP by 1%).

i started with 1 rank in whatever-skill-my-book-is-in and manathrust is grayed out. With "G"et i have no skill points. Or rather, i have 3 points in Magic, 1 point in Thaumaturgy, and that's it.
Oh and i died to a sparrow in town.

Ah, Thaumaturges are an exception; they have "innate" spells that don't come from spellbooks. When you hit 'm', there should be an option like "cast a Thaumaturgy spell" or something, which lets you bring up your list of randomly-generated thaumaturgy spells. I recommend making a keymap that does "m@cast a Thaumaturgy spell\r" (subbing in the actual text of the menu option if I misremembered it), which lets you go straight to your spell list with a single keystroke.

For what it's worth, Warpers make better thaumaturgists than Thaumaturgists do. Warpers get great multipliers in several important utility realms, in exchange for a .7 multiplier in Thaumaturgy; it's a worthwhile tradeoff. However it does mean starting the game with no offensive spells, so you'd better figure out some way to get your first level. Flinging flasks of oil at monsters on the overworld can work.