A: There is no requirement that you be read your rights before, during, or after your arrest. If you are questioned while in custody and the police wish to use your responses to those questions against you in court, they are required to read you your rights first.
A: You will likely be scheduled with another court appearance so the judge can address this on the record. It is not a given and you would be wise to have an attorney represent you at that hearing.
As to your second question, yes. It is always better to have the blessing/approval of your probation officer.