I don't know if this is intentional, but apparently I can't even do the very first research. It requires crushed stiralite, which is impossible to get because I need crushed Stone for that, which I get from crushing stiralite. Am I overlooking something?

Been a while since i started a new game, but I think you're given an Electrolyzer, which will give you slag, which you put through a machine to get the crushed stone.

Look at the top left of the screen for the FNEI app. Learn to use that a LOT. It's a life saver in this modpack.

This pack is insanely complex, almost like a whole new game.

There are multiple ways of getting crushed stone. The way you are looking for is to crush slag - using the burner crusher that you started with. Slag is acquired via an electrolizer. You will need to craft this, along with flare stacks to vent the resulting hydrogen and oxygen.