Again, if you're not seeing a full day's worth of use most times over the next week, return the Watch for a different one.
There's nothing that says you have to keep the devices charging near your bed. But, even if you do, there are some very nice, attractive charging stations.
Charging your phone overnight is best practice because, if your phone is plugged into power, connected to WiFi and has the screen locked, it will automatically back itself up to iCloud (assuming you have that feature enabled). Not only will you start each day with a fully charged phone, you'll also never lose more than about a day's data should something untoward happen to your phone.
I don't always charge my watch overnight. I often put in on to charge a couple of hours before I go to bed. That way, if I want to wear it to track sleep, it's fully charged. I put it in airplane and theatre modes for the night. In the morning, I drop it back on the charger while I'm showering and dressing. I usually end the day with about 30% charge.