Once you’re comfortable with how quickly things can go south if you play badly, I recommend the Eternal Lords campaign. Imho it’s the best one.
Golden Realms campaign is pretty good, but mission 2 can be frustrating.
Orc Warlord is in some ways a noob trap. You have tonnes of melee damage, little range and poor resistance to anythign that isn’t physical damage, and there are many many sources of non physical damage. Be careful or your tough Orcs might get shredded, very quickly, by a bunch of Undead or even just a bunch of Goblin darters.
A solid starter combo is actually Orc Theocrat because Theocrats have lots of healing, Orcs heal more if they win a fight and start with 5 bonus HP, and Theocrats also have lots of tools to mitigate low resistance.
Basically they hit hard, and can take a punch normally, but now they can be healed quickly (= more fighting) and take less damage (=resistance boosts).
Take creation adept and get heal and bless. That combo makes your t1 infantry very tough indeed, and your Crusaders arguably the best in the game (Dwarves are pretty good too though).
Get mark the heretic asap and watch your stacks melt the independents. Downside is not so great mobility until you get Exalted and Shrines.