what do I say?
when do I tell them , as I request taxiing ? takeoff? in the air? when they tell me to do something I don't wanna?
doesn't it sound a bit sad to broadcast that over the air?
why do I care
You say almost exactly the same things at the same times you have done in the lead-up to your first solo. The only difference is that you preface your call sign with the word "student". That way, ATC (who should be aware anyway) but more importantly other pilots in the circuit, are aware that you are a student soloing and will be helpful in ensuring your circuit is uneventful and more importantly, enjoyable.