Hi,
I previously did a DIY 3D2N in Ninh Binh.
I think there are shared minivan transport to and from Hanoi. You can also arrange for private transfer. Previously I stayed at a homestay in Ninh Binh and the host arranged the transport back to Hanoi for us. But the minivan dropped us outside the old quarter to avoid the jam and we had to take a taxi to our hotel...
Which area of ninh binh are you thinking of staying at and what are you planning to visit? Which month? Some attractions are closer to one another and within cycling distance. I've seen blogs featuring their cycling itinerary so it should be doable. Although level of fitness and the weather may be factors that affect how enjoyable your ride is. When I went previously I cycled from my homestay to Trang An on the first day and a motorbike guide took me around some other attractions on the second day.
- I stayed at An Phu homestay years ago when I visited Ninh Binh. Really cosy and clean homestay with great breakfast and tasty dinner. Just that the location isn't exactly near any attractions. The homestay is located in a residential area and there also weren't any eateries around (not that I was aware of) so we had dinner at the homestay. But it was really peaceful and I enjoyed my stay