Most likely problem is your multifunction switch, but you actually need to perform diagnosis to know for sure. While that would be the most likely cause, it's not the only possible cause, and you need to narrow it down and figure it out if you don't want to end up pissing a bunch of money away throwing parts at it needlessly.
Change the front turn signal light bulb. It's bad.
Forget to take out the key
If it's just one way and it wont shut off then its probably just to turn signal switch.
If the turn signal bulbs light but will not flash, the flasher relay is defective, replace it.
turn signal relay fuse
Check the signal light fuse, the signal light relay, and the signal light switcher.
Check your tail lights they are probably out also. Most domestic cars power the dash lights off of the tail light circuit so you will know when the tail light fuse blows. Check the tail light fuse.
One of four things can cause a turn signal not to work. Either the turn signal switch assembly, a bad bulb, a bad fuse, or a bad turn signal flasher.
Brake light switch went bad.
multi function switch( turn signal, lites etc)
replace turn signal flasher, hazard flasher is separate
Check for a bad socket Turn signal flasher? Switch at steering column?