Obtaing an NPI and need info on the medi-cal provider process

Last year I worked side by side with an LVN who worked independently for 18 yrs. He found his own medi-cal patients, checked eligibility on his own and was the sole provider for each of his patients. He explained the process to me and I have obtained the NPI number and printed the provider application. Im feeling a bit overwhelmed and would like to know if there are lvn's that have taken this route and can share some knowledge and advice?