Hello,
ENG MODE selector: IGN/START: If cooling is displayed on both engines and you have the dual cooling push button available, Then you press the Dual cooling push button.
Then ENG 2 Start: At about 18% Indication of Ignition A or B and Fuel Flow increases
20 seconds max after fuel is ON: EGT increases and N1 increases prior to 48% N2
At approximately 55% N2 : Start valve closed and Ignition OFF.
I would not worry too much about learning these values by heart; What is more important is to know the correct SOP related to engine start and especially for abnormal. Airbus is great and ECAM will tell you what to do in case something goes wrong except in 3 cases I can think of: N2 high vibration (VIB>5 on PW engines), LOSS of ECAM display, or tail pipe fire. In these cases you will have to shut down the engines by yourself. I had also a case where the starter motor had issues and sparks was coming out of the cowling and maintenance asked us to shut down the engine immediately. In 10 years + flying the Baby Bus, that's the only time I had to shut down the engine without ECAM. In the simulator I have a TRE who loves to give engine start with zero oil pressure and also no ECAM in that case. The oil pressure is also not monitored by ECAM but surely if no oil you will have other engine indications who will spike up...
One Mnemonic I found pretty useful which is valid for all jet engines during start: SNIFENOS: Start valve Open, N2 increasing, Ignition ON, Fuel Flow Increasing, EGT rising, N1 rising, Oil pressure rising and Start valve close.
Enjoy the Type rating!