As a rule, LA is... weird... It's the end of the world, and the factions are in full apocalypse/ragnarok mode. Ermor only has undead left, R'Lyeh makes your own heroes mad, etc. It's probably a better idea to learn the game in EA or MA, depending on whether you want (even) strong(er) magic or not. Keep LA for later, it's great to explore some alternative over-the-top flavour of the factions still around. It's cool lore-wise too as some factions have been wiped by others, some have been assimilated, and having played EA/MA, you'll pick up on that stuff when moving to LA.
EA Ulm is typically a bit of a challenge faction, being mostly non-magic men in an era of spellcasters, giants and monsters. It's far from unplayable, but it's a counterintuitive faction for the era. MA Ulm would be more of a typical era fit, in a less magical context where their steel is king.
For blood magic, Mictlan is the go-to faction, although I could never really make them work, so I get my blood fix with Abysia. Not as blood focused, but you have access to it, although you'll want your pretender to have decent blood skills to complement it.
Unless things changed from 4 to 5 otherwise, something critical you'll want to do early is to hire mages with access to various spheres (and increase their magical skills through items when possible, like Thistle Mace for +1 Nature, etc) and have them explore your territory for magic sites. Each site has a sphere and a level, and you'll find it if the mage at least matches it (say you're Fire 1 Air 1 Nature 2 Blood 1 and the territory has a Fire 1 site, an Air 2 site and an Earth 1 site, you'll only find the fire site). These sites will produce the critical gems that are required for pretty much all the powerful spells. The difference in battle between a fire mage with or without fire gems is like day and night (provided that you researched the fitting battle spells).
