Yeah I'd suggest turning off a lot of the options and AI plots when you start, maybe picking one or two. Would definitely turn on "Show AI types," and probably also "Human resistance fighters," which helps you without any cost. It doesn't cost anything to turn on golems easy and spirecraft easy, so you can leave them on and experiment with them when you feel like it; if you lose them you're out some resources but otherwise just back to where you'd be if you hadn't turned the options on.
Also strongly suggest looking at the Wiki on gate raiding and whipping boys and either looking through the fora or asking about them; the really experienced players have written tons of excellent stuff about general strategy under topics like that and I find that when you ask them they're pretty much always happy to write more.
But about golem self-damage; it will stop if you power them down (do this by clicking the yellow play/pause button in the lower-left when you have them selected. They golems won't fight when they're turned off but you can turn them on when you need them. You pretty much want to put all your golems in low-power mode when they're not fighting (except maybe hive --- it might need to be turned on to build its swarm ships). This is also true for Neinzul Youngling fleet ships, which also self-damage, although there's been some talk of changing this.
Any golem can be used in both offense and defense, but many of them aren't meant to slug things out on the front lines. The armored golem definitely is, but artillery and cursed are meant to snipe from a long way away. The botnet mops up enemy fleet ships and turns them into "zombie" (uncontrollable allied) player ships, so it's probably easier to use against waves. Then the regen and hive golems have peculiar abilities that aren't for direct combat but are very useful when you're attacking a world --- if you're going into a really dangerous world you can clear a space for them and then let them hang out away from the fighting while they support your fleet. I haven't used the Black Widow golem and don't get it, I'm afraid.