How do I fix brake and turn signal lights, '97 Suburban?

How do I fix brake and turn signal lights, '97 Suburban? I am driving my boyfriend's 1997 GMC Suburbanwhile he is out of town. My turn signals and brake lights do not work but my tail lights work. How can I fix this ASAP? I just got a ticket for defective equipment for $130 so i gotta fix it quickly.