This article has the information you're looking for. https://themortgagereports.com/413/credit-check-fico-mortgage-rates
But the short answer is that rates and programs vary widely between lenders, so the best and easiest way is to get a lot of quotes. That's simple to do on our site. The other things you can do are making sure that you are an attractive candidate for a loan -- add a few points to your credit score, buy a house within your means, and keep some savings in reserve for emergencies.
If you can get a seller to cover your closing costs, you can make a larger down payment, pay off some bills, or have more savings in reserve. All good things. https://themortgagereports.com/29154/get-sellers-pay-closing-costs-to-pay-your-closing-costs
Thank you for your question, and good luck.