A fellow male student verbally assaulted me on my school bus, saying he was going to kill me and ‘mess me up’, what legal options do I have to help keep myself protected?

Junior high, senior high? Report it to the School Administrator - or have your parents report the incident.

If it's a thread you can also notify the Police.

What State?

I moved this from small claims court ( since you can't sue for this) to criminal law.

1. this is bullying ( spelling? ) and should be against rule in all schools

2. your parents needed to file a police report the day it happened when you told them about it when you got home.

3. many ( I know not all) buses today have recording equipment on them, so if told soon enough, a record of this may be available