Hi Fiona - the best of luck to you. I can't say I've much relevant experience myself, except that one year I took my sons aged three and nine camping on the Mediterranean on my own, the first time I'd ever driven 'on the wrong side'. Also one year we did meet a lovely Dutch woman who was travelling around France in a tractor with a gypsy type caravan on the back. She was 'on her own' with her dog - and had been travelling for several months. Her progress was obviously slow, but she said that had helped her make more friends, and make the most of the weather! I must admit my experience of being a 'single' woman was very similar, in that people were all extremely helpful and friendly, and helped me join in whatever was going on.
I'm sure you'll have a great time.
Obviously a prime consideration is security. My advice would be to always stop on proper campsites with other campers and caravanners around you. I haven't 'done' Denmark or Poland, and 'done' Germany only a couple of times, but you'll find some lovely sites, I'm sure. Take a look at the Camping Cheque website, www.campingcheque.co.uk for a range of sites for