Congrats! If you're working with a realtor, they will tell you exactly what to do. :) Our realtor was awesome!
You'll need to officially apply for a loan (if you haven't already done so). Your lender may require a lot of paperwork- copies of the offer letter and acceptance, your W2s from the last two or three years, proof of employment, photo ID, social security card, bank statements, they'll check your credit, etc.
You should also set up a home inspection and plan to be there during the home inspection. If you find things that need fixing during the inspection, you can ask the sellers to fix them before closing (again, if you're working with a realtor, they'll help you out)
The home will also need to be appraised (our lender took care of this for us, we didn't have to do anything) to assess the market value and if it's selling for a reasonable price.
Before closing, we had a final walk through of the home to make sure everything was "as we remembered" and the repairs were fixed.
At closing you'll need your down payment, closing costs, fees for the title of your new property, etc.
The step that took the longest for us was our lender was incredibly slow. They did not submit our loan for underwriting until the day we were supposed to close. It took three times going into and out of underwriting before we were approved. We closed later than expected and had to move out of our temporary housing, the movers were upset, etc. It sucked. I hope it doesn't happen to you!
Anyway, we closed about a week late. After our offer was accepted it took about a month to get the keys to move in. We gave the sellers 24 hours after closing to move out but they'd already moved out a week or so earlier.
Another potential "hiccup" is moving out of wherever you're currently living. We moved across country and into temporary housing.
did it this summer