I'd argue the "how" is at least as important as the "what." Ask questions - and really listen and try to understand why he does things that way. Explain your own what and why, and listen to his responses. Talk together about what makes sense for both of you. Absolutely talk about logistics -- do you want to combine finances; if so, to what degree; if not what is a fair split? But also talk bigger-picture -- what is worth taking on debt for; is debt an emergency or normal part of life; is credit card debt ever worth it and if so when; how big of a house do you want/need; how does that weigh against other wants/needs? And then dream a little about your future -- kids? If so, stay at home, daycare, family, nanny? How important is FIRE vs current needs/wants? What is your vision of FIRE - work forever for less pay, volunteer for charity, sit on a beach, turn your side hustle into a full-time business, etc.?
The point of these discussions is partially to get specific answers and make some decisions, of course, but the much-more-important goal is to reveal the unspoken assumptions that each of you have -- the areas where you just assume that your way is the way everyone does it, because that's what you know. Those are the areas that create friction, usually because you don't even know there is an issue until you are already pissed off. E.g., the day my DH told me he had broken his sunglasses (ok) and came home with $120 Oakleys instead of the $10 drug store version that I assumed he was picking up. Or the day we argued about the vacation plans, because he had the silly idea that budgeting in a category meant it was ok to spend whatever you budgeted (I always budgeted for less than available income, and then tried to come in *under* budget in every category). It wasn't about the glasses or the vacation -- it was because I grew up poor and assumed that you never spent more than the absolute minimum on anything, while he grew up UMC and assumed that money always appeared when needed, so he should get/do what he wanted. We of course knew of each other's backgrounds before we got engaged, but we had no clue how much it affected those kinds of day-to-day decisions.
FWIW, there is no objectively right or wrong answer on combining finances. I know I've said this before, but when we married, my SIL told me that our decision to keep $200/mo each separate as "play money" meant that we were not fully committed to the marriage; meanwhile, my mom thought we were nuts for combining anything. And yet my mom and stepdad were together 38 years with completely separate finances; my SIL is at around 23 years with their 100% share; and we are at 21 with our in-between approach. The only "right" answer is the one that works for the two of you.*
*Our $200/mo. "allowance," for ex, was a direct response to the sunglasses incident, so he could buy stupid shit and I couldn't nag him, and I could save mine and so come in under budget. My SIL's approach (mutual agreement on every purchase) would have destroyed our marriage within 5 years - I'd nag and he would shut down, and we would have quickly become sources of conflict for each other instead of sources of strength and support. As with everything else, YMMV.