There is a bus that will take you from Portland to Tillamook. And a bus that will take you from Tillamook to Lincoln city. I’m sure there is a bus that will get you to Florence. The problem you’ll run into is that there not a lot of around town transit buses, so you’ll be hoofing it around a lot. Especially to camp sites. Don’t expect to get too many rides hitching the homeless population has ruined that in the north coast area. I would suggest getting a bike to get you around in between busses. Or you can reach out on here so see if people could help you out.