What are some of the things you did or wish you did prior to filing for divorce?

Things are headed for splitsville and I’m trying to prepare myself. I haven’t even talked to a lawyer yet, although I’ve read most of you say to meet with a bunch before deciding on representation.

We have been married for 20 years and the kids are all over 18. What can I expect for alimony (I make considerably more than her)? I assume assets acquired together will be just split 50/50 (WA state).

I feel like I should file before she does. I don’t think it would be a messy divorce, but I can see her trying to apply for college or some other scheme to get more out of this. I honestly just want her to take everything (except the house) and I just want out.

Sorry, let me know if you have any good suggestions for a noob.