Ok, I'm most of the way through the process so what I've learned.
If you go to court the lawyers win!
Aside the courts generally favour a clean break, both parties need to be adequately housed so if you own that means both parties can buy ideally. Adequately housed doesn't mean spare bedrooms.
Over 10 years assets brought into the marriage are not taken into account generally, everything goes into the pot, 50/50 is the basic assumption but will differ in some circumstances (I'm getting 65% for instance and and 5 years spousal maintenance).
Individual circumstances do come into play eg I have an adult dd with asd that requires housing.
It's tough, especially as you found out this way but you can be ready by ensuring passwords are changed, vital documents secure etc.
I cannot stress enough though that keeping it amicable will be better for you both. Dp has spent £££ on his divorce, I spent £550, filed online. Exh and I made a spreadsheet worked out jointly the costs, he agreed to rent for a year to sort things out, he's now buying me out.