I live 6+ miles out of Sandy. Are there cars that act like lyft services out this far?

There is always the bus. There are 2 lines that go up the mountain past the town of sandy. One will pick/drop you off anywhere you want on the highway (as long as it is a safe place to pull over) and another that only does stationed stops (you can look online to see where those stops are) Its $2 each way.

I try to get a Lyft, no service in the Sandy area.

You can maybe get one depending on where you're at. I only know that gresham offers it and the closer you are to gresham