My First Project: DC motor car

Hi, I’m new to Arduino (and programming, though I have a light understanding of electronics) and I’m excited to be here among a group of creatives. This will be my first project and I’m hoping to gain more skills.
I’m after some guidance for my device I’m building for my class.

I’ve proposed the vehicle to have 2 rear wheels run by separate DC motors (cheaper than servo I’m guessing) so I can perform u-turns/3-point-turns; the front wheel is a caster wheel (aka swivel wheel). To perform the turns the DC motors will need to be able to turn both directions (is a H-bridge needed here?).

How would I go about programming my device to run by itself? i.e. no remote control: just run off a set of instructions.
Is it possible to use the ATmega328, after programming, away from the arduino board on a separate breadboard?

I have an Arduino Uno, and am yet to buy the rest of my components - would also like some directions with this too.
Any advice and links to relevant web tutorials is greatly appreciated.

-RBG

If you search the forum (esp robotics subsection) you will find many examples. The search field is inthe upper right corner.

Said that, one often used configuration is based upon a distance sensor. A core to start with sounds a bit like:

distance = measureDistance();
if distance < 10 cm goBack();
else if distance between 10 and 20 goRight();
else goForward();

So you need a distancesensor in the range 5-100 cm

Other configuration often mentioned is a line follower. Shine a LED to the floor and e.g. use 6 LDR’s to spot the position of the line and have it control the movements. Detect crossings split-points etc and build a stack of choices you make. When you have to go back you can take another decission at the last split etc. Then it becomes a (brute force) mace solver.

It is possible to use the ATmega328 without the board, but if you pull the chip, your board is useless for other project unless you buy more chips, I heard buzz however, that the ATmega328-28pin DIP is on its way out of production, so the supply will soon dwindle if this is true, they are switching over to surface mount versions of it. but thats just a rumor I've heard.
As far as the programming is concerned, I'm a rookie with the code too. wish I could help.

Thanks for the reply.

Is there a method that does not use any sort of sensing? Ideally I'd like the vehicle to move along to preset instructions

In the meantime I'll further research distance sensors.