There are several classes needed to meet the requirements for Fireline EMT. I believe the Firescope manual lines out all of the classes you will need.
Something that is not required but I highly recommend is time on a hand crew and time on an ambulance. These two things in addition to what is required will make you the best Fireline EMT you can be.
The time on a hand crew will give you the knowledge you need to keep yourself safe on an incident. The time on an ambulance or as a firefighter/EMT or PM will give you the knowledge to treat your patients with the utmost care.
Certifications are one thing, on the job experience will take to the level you will need to be at to provide the care that is needed.
Good luck,
Chris