I have just purchased it - Help !!

[fitfit]

Hi all, yesterday i just purchase my new yaris / automatic.
i have some questions in it so if anyone could help ?!
1- while i'm on the D mode, can i hit the overdrive while i'm puting my leg on the accelerator ? or shell i leave my leg then hit the overdrive and get accelerated again using this mode ??
2- what is the L and 2 modes are for ? (sorry i'm a manual user for over than 7 years ) so i dont have any idea !!.
3- i dont know if it can get me up to 150 or 170 KM/Hr. as when i get to 120 KM/H i find that it doesnt accelerate the same rate it does from 0 to 100 ? or shell i do the overdrive mode to get a top speed ?

thanks all and have a good drive