Yay for your first trip ever to DLR! How exciting!
No need to be confused.

Fantasmic is a nighttime show that takes place outdoors on the Rivers of America (in New Orleans Square at DL). It is an amazing multi-media show that takes a journey into Mickey's imagination. There are over 30 Disney characters, princesses and princes dancing, a captivating battle between Captain Hook and Peter Pan and the Lost Boys onboard a pirate ship, and many other elements including fire, fireworks, music, and wonderful movie scenes shown on water movie screens. I would say it is the best show at
Disneyland.
Depending upon when you are going, there are either 1 or 2 shows a night.
Viewing it:
There are a few options. All have pros and cons. There is a sitting area right along the waterfront. People camp out here saving spots starting hours in advance. Truly.
There is a standing area just behind this area that fills up, but not as soon.
All of this is free.
You CAN purchase the Fantasmic dessert package ($60 for adults) to sit in the limited reserved area. You get a chair, a dessert box, beverages, and service. Some like it. I personally think it is more fun to watch Fantasmic with the crowd. It's a personal preference.
There is much more to the "where" to watch from, but this is the general concept.
You can absolutely find video of Fantasmic on
YouTube if you want, but I am one who hates to peek at my presents before opening them. Your choice.
HTH,
Dreams