Knowing the finances before anything starts
Start by learning what exists: income, accounts, debts, retirement plans, insurance, and property, and where the paperwork for each is kept. Pull your own credit report to see which debts are in your name alone and which are joint. Make copies of household financial records you have lawful access to and keep them somewhere private. If you have relied on your spouse to manage money, this may take time, and that is fine, because your lawyer can obtain the rest through disclosure once a case begins. Avoid getting into your spouse's personal email, phone, or password-protected accounts.
Moves that are hard to undo
Moving money out of joint accounts, running up debt, or hiding property tends to be uncovered and held against the person who did it. Leaving the home can affect later arguments about parenting time and about who keeps the residence, so it is worth discussing with a lawyer first unless your safety requires leaving now. Posts about your spouse or the marriage online can end up as evidence. If there is abuse or a risk of harm, safety planning comes before everything else, and an order of protection can be sought right away. Once a case is filed in New York, automatic orders limit many financial moves anyway.
A meeting before anything is filed
Talking with a lawyer before filing helps you decide on timing, whether mediation is worth trying, and whether any temporary orders will be needed at the start. We go over your goals, your financial picture, the children's situation, and any agreements you signed. That conversation is confidential, even if you are not sure you want a divorce at all. Bring what you have gathered and a list of questions; it does not need to be complete. Many people leave a first meeting with a short list of next steps rather than a decision, and that is a reasonable place to be.