The different dialects of the US: my take on them as an American. Whats the diff b/w a midwest and cali accent?

Have you also noticed iN NY particulary long island that a's can be pronounced as ers....example Lisa becomes Liser. I grew up in N.Y. and CT and had parents who were southern so I also don't have much of an accent. My Dad is Texan and he pronounces wash like warsh. Oil is Ol. Also I went to school in Texas and we never said do you want some pop we always said do you want a Coke or let's get a Coke even if you really wanted a 7UP. Coke replaced soda. I think Midwesterners definitely have an accent but it is hard for me to say exactly what is different. Everyone I have ever met from California doesn't seem to have any accent.