To be sure your beer is done fermenting you can take SG readings a few days apart and if they remain the same your beer is done. If it continues to drop then wait a little longer and test again. If you bottle before fermentation is done you risk creating some bottle bombs.
As far as watery, it might just be the lack of carbonation at this point that is throwing you off. You said you followed the instructions on the kit so I would doubt you used too much water.
Tap 1: Zombie Dust Clone
Tap 2: Sour Experiment
Tap 3: Blonde Ale
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