Even if they haven't worked with an NP before, the practice should be familiar with the process because it is very similar to a new physician who is applying for NPI number and DEA license. You can do these on your own, however.
To apply for NPI, go to: 400 Bad Request
. You basically create a new account. This process is a free so just follow the steps on that website. While you may not be required to list an employer, you should associate your NPI number with the practice you're working under.
To apply for a DEA, go to: DEA New Registration Applications - Welcome Screen
. This is not free ($750), so you should check if the employer will pay for it. Also check with your state if you need additional documents before applying.
Best to speak to the practice manager or whoever is in charge of physician on-boarding where you will be working. You will also need to be enrolled into Medicare. The practice should be fairly familiar with these requirements.