I found a Apple Watch
Yes I found one Apple Watch, can I use it?
Question marked as
NO. Why would you even think you should be able to use something, which isn't yours in the first place? The watch is most assuredly Activation Locked, so don't even try to use it. Apple won't help you. We most definitely won't help you.
Do the RIGHT THING and turn it over to the local authorities so whoever lost their watch might be reunited with it. Or simply recycle it as its TOTALLY useless to you.