In my experience you only ever need to ask for start either
a. on an IFR flight plan (so ATC can get themselves in gear!) - won't apply to you yet
b. at big airfields with an ATIS - and the ATIS occasionally says 'all aircraft call for start on XXX.XXX'.
Even the RAF base where I fly doesn't require a call for start for club aircraft, though oddly there is a military habit of calling 'complete, closing down' before shutdown.