I have graph $A$:
I have graph $B$:
Are graph $A$ and $B$ non-isomorphic because?
I think yes, because:
graph $A$ has $V_{8}$ with degree vertex $4$ and graph $B$ has $V_{8}$ with degree vertex $2$.
or vertices $V_{8}, V_{1} $ in graph $A$ are neighboring, but in graph $B$ vertices $V_{8}, V_{1}$ are not neighboring.
Is that correct?


No, this is not correct. For example, your first bullet point only shows that $V_8$ in graph $A$ cannot correspond to $V_8$ in graph $B$. Why can't there be an isomorphism that takes $V_8$ in graph $A$ to some other vertex in graph $B$? (I am not saying there is -- I have not checked -- but your argument is not sufficient to prove that the graphs are non-isomorphic.)
Remember, the labels are not part of the graph and are just for convenience in identifying particular vertices.