Re: whats a good distance
You have some good fly fishing in your neighborhood. If you are picking up and false casting 30 ' and shooting 5' or 10' you are doing fine to learn. That is plenty of distance to fish in many situations. You need to work on making good loops, shooting line, roll casting, mending, and left/right reach cast. By the time you learn these cast your distance will take care of its self.
You should not be concerned about distance at this place in your skill level. Trying to get more distance will just result in learning poor techniques. When you can say you are confident in your cast and you can toss a pretty good loop with little effort, then think about increasing distance.
I suggest you measure out 30' of fly line and then mark the link where it lies under your finger on the grip. That is, cast out the line on the grass and let it fall to the ground. Now measure 30' out of the tip of the rod. Pick up the rod and hold the fly line against the grip with your fore finger. Take a black marking pen and put a half inch mark where the fly line is under your finger.
Now when you want to practice have that mark under your finger and the line held tight against the grip. You will then have 30' of line out of the tip. This is how you should practice casting. Make sure you are using a leader and a small fly with the hook broken at the bend.