Alright, I've got a question I have no flotation in my new boat if I filled it full of water in the lake will it sink ?

No, it will not sink to the bottom. It will float very low. You will not be able to get back in and paddle it. If you capsize in the middle of a lake, you may need to abandon your boat to get back to safety.

It is a very good idea to have reserve buoyancy in the form of air-tight bulkheaded storage chambers or float bags. I like to put float bags in my hatches.