If nothing got on the logic/mainboard, you're okay, however a spider peeing on it can kill a Mac mainboard (seriously) so you need to REALLY look it over carefully. Macs are TERRIBLE about fluid damage, just as they are terrible for repair, they're built like a cell phone, not a computer.
If you find water damage on the mainboard but it still runs you might be okay, but odds are it's damaged. Check in the areas you see damage and make sure no contacts are completely eaten away and clean that spot off with some alcohol then let it dry for a couple days or stick it in a VERY low temp over like a toaster oven after cleaning with alcohol. Since it comes on, chances are it's usable, but you may have taken out individual systems such as Thunderbolt. If it is serious though... More on that in a moment.
The keyboard is probably toast and they are glued in with industrial double sided tape and plastic rivets. Yes, you can replace it, but after watching a specialist do this, I would either buy a new chassis with keyboard in it or send it out to an expert, it's a nightmare to do properly from what I saw. The keyboads themselves are cheap, but a top with keyboard isn't too bad.Touchpads are similar to the keyboard, but easier to replace. Keyboards and touchpads will keep it from booting, so if the mainboard/logicboard is okay, you're ahead of the game. You can use anything from 2012- 2016 I think, so parts are easy to get.
My guess is you need at least a new keyboard and touchpad, you can do it yourself for probably $100 (my advice, buy a top/keyboard/touchpad combo so it all remains factory sealed). If it's more than that, just replace the whole computer in it's entirely. Seriously, the prices on logicboards are just silly and you can often replace the whole thing for the same price then sell off your old parts that still work (especially if it's an 11.6in model). If you do replace the logicboard, you need to find out the exact year as Apple used proprietary drive connectors and replaced them every couple years (thanks Apple!). If you do replace the whole thing you might be able to unplug the keyboard and touchpad then use a usb mouse and keyboard to get your data off, though my concern is that they tend to not boot at all if that is the problem. It getting part way in then failing is not the norm, but that could indicate only the touchpad is shorted.
