Can I just walk in and renew my DL and take photo all in the same day and be done with it?

Yes

Sure you can do all that there

I'm not sure. But usually you receive a renewal application in the mail..you can fill it and send back or you can do those steps on the penndot website. You can pay the fee online and you'll receive and temporary update license..while you wait for the photo card to come in the mail. Then take the photo card and your expired license if you have it with you. Not sure if you can just walk in for that service...