We used a travel guide company in Beijing for all of our travel called Thechinaguide. They provided us with a guide named Henry Lee. He was excellent. Ask for him

Hi Sora, Moon Hill is about 8.3 km from Shuidongmen pier and depending on your cycling speed it will take less than 1 hour.

We did the bike ride along the banks of the nearby river and ended up at the cafe at the foot of Moon Hill. The bike ride was comfortable with not many hills to climb and I found it relatively easy and I am a 71 year old guy. The distance we covered was around 15/20 Kilometres but the bike ride was beautiful. The walk up to the top of Moon Hill is not what I would call an easy stroll but neither is it too difficult. There are steps that take you to the top and the views, once you reach the top, are lovely. It is well worth the effort and there are places where you can stop to catch your breath if needed. Enjoy your trip. I'm jealous.

I never saw a glass water bottle my entire trip, there are sealed plastic water bottles everywhere in china. I was in the country for 2 weeks and had the local water in teas and coffees and it is safe. I wouldn't drink river water but regular water is just as safe as where I live in florida.

If you have a chain for your bike you could chain it to a tree in the parking lot. The Moon Hill Cafe is right off of a main road and there is a gravel parking lot to the right; that is the only place I could see a bike being parked. It is a safe area if you wanted to just leave it unchained but I understand some people don't feel comfortable doing that. The trail to the top is directly to the left of the cafe.