It's legal to pull over a car for swerving, even if it's swerving because it's "only" driving too fast for the weather conditions. Different states have different conceptions of "swerving" - in some states you can't be pulled over unless you "swerve" across a lane marker, fog line or center line; in other states you can be pulled over even if you stay in your own lane. Tell us more about the swerving.
Miranda rights are only relevant to custodial interrogation.
See if you qualify for a court-appointed lawyer.

