Hi Mrs MoW
Our caravan (Abbey620) has a microwave fitted and we use it for making quick porridge for breakfast, it tells you on the box how to do it and the times etc. The only thing to watch out for with porridge is that it doesn't get to hot and boil over the top of the container, leaving a mess to be cleaned from inside the microwave, you have to keep your eye on it.
We also use it for heating quick ready meals, shepherds pie and that sort of thing, and it is useful for warming sausage rolls if we come back from the pub with friends.
Soup, rice pudding and anything like that is also an easy option.
Most packaged or tinned foods wil state whether it is microwaveable with warming or cooking times printed on the packaging. Make sure that the container that you use to microwave in is suitable for the purpose, tins and foil are a no no as are any metal objects.
We would never cook meats from raw in the microwave, and if you want to do poached eggs there are plastic containers sold in 'pound shops' that are suitable( I'm sure we've got one somewhere)
Our microwave is mounted on a level with the top lockers in the kitchen area, and as we are both of short stature we bought a little plastic step, again from a pound shop, which is useful and ensures that we lift hot food down to table level safely and without spillage.
One other thing to remember is that the food is still cooking when it is removed from the microwave so if you have heated up sausage rolls for instance you have to take care that the centre, in this case sausage, doesn't burn your mouth.
It's essential to make sure that food is properly cooked or warmed through, especially from frozen, apart from that it's quite simple, so enjoy the new caravan and the microwave.