My 2p on your situation:
Buy the Yaris for your first car. Its may not set the world on fire, but it is a decent, reliable car and you are not stretching yourself to buy it and run it. As and when you get more experience as a driver you will no doubt get bored of it, but by that point you will (hopefully) have a much clearer idea of what care you want as its replacement. Rather than picking something now that may be a bag of nails or you may decide is unnecessary, too expensive to run, too fast, too slow, too big, too small etc..
Double that to make it up to 4p. Sound advice.


