Can I access the watch without knowing the previous owners Apple ID ?

The person that you bought this watch from needs to follow all the steps in this link;

Prepare the watch so the buyer can use it.

If they can't or won't then get your money back or recycle the watch and put it down to experience.

You won't be able to do this. You'll need to contact the previous owner for assistance.

About Activation Lock on your Apple Watch - Apple Support

Activation Lock is a theft deterrent feature with no bypass or workaround.

Without the owner's authorisation (Apple ID & password), no thief or anyone including you can re-use the device.

I bought this Apple Watch from a store and it has an activation lock on it and it says I have to have previous owners Apple ID how can I get past this

You can't. Return it to the store you bought it from. It's useless.