What you want to do is talk to a loan originator to get pre-qualified. This will not require a credit check and but will be based on the verbal qualifications that you provide. Once you find the house you want to buy, the mortgage lender will then pre-approve you by conducting a credit check and verifying the information you supplied for pre-qualification.
If you are legally seperated, your impending divorce should not have an impact on your qualifications, but you will be advised by some to wait until the divorce is final. Your preferred lender can give you specific information. If you would like a referral to a qualified, dependable lender, just drop me a line. I'm happy to help!