Ghost is right, change tires first coz stock tires toyo J50 not really good. Especially ppl like to brake hard during test drive to test out the brakes. So not sure of your tires condition now.
Since you newbie, maybe can get a garmin gps around 2~300++, so you always know where u are and where to go

Then you can consider change the horn, coz latio horn is not powerful and some may ignore
If your car comes with solar film, then good. If dun have then can consider, reduce the heat when driving or parked under hot sun
Since yours is test drive unit, better get a shampoo to thoroughly clean your car of bacteria and germs that maybe accumulated after those test drives
For spark bridge, VS, fierce front grille, headlight, please consult latioboy and the rest mod kings
