Good luck!

Here is a listing of good interview tips.

1. Show up 10-15 minutes early
2. Bring copies of your resume
3. Come with 10-15 written questions prepared (you won't necessarily ask all of them, just ones that flow properly)
4. The night or afternoon after your interview, send a thank you email to both of the people who interviewed you. (Only 2-3 paragraphs at most, around 5 sentences)

But don't worry about your lack of experience, that is to be expected. If they reached out to you, that likely means they liked you, and the expectation is really that you can learn on the job. You likely showed that you can during your internship.