If so, what tow bar would we need and any other suggestions you may have.

Depends on the kerbside weight of the car and the total weight of the caravan. Van cannot weigh more than car.
The tow bar would be specific to the model of car.

not a good idea it will strain your engine and you will soon knock the clutch out

No l do not think so , l would not try it even with a tow bar the tow bar may be strong enough but the wear and tear on the car may be permanent, hope this helps,

no, no, no, and no, sell the caravan!

It depends on the caravan is weight.
Remember to add the weight of anything you have put into the caravan (food, clothes, cutlery, crockery, tv, toys, etc.)

You can check car-caravan compatibility at http://towsafe.co.uk/