U just reminded me the time wen i was a teenager like u & got fedup like u & many others. So just after joining the "fedups club" (Thanks to Levin for selecting such a good name for club). I started to do it my self & Alhamdulillah for last 17 years i have learned alot & quite satisfied too.
Talking specifically current issue of ur bike, its facing lean mixture problem @ idle so no need to change needle valve setting (High Jet).
As first step just open the right side Carb Cover plate of ur bike & u will see the Carb in front of u. There would be round intake duct in the center of the carb & through this duct u can see slide & Needle jet ( As mentioned by YAMAHA 135) inside the carb Housing.
On the fornt side of duct there would be Golden Colour Screw might be having a small needle size hole in it, that screw is the mixture setting point of air & fuel for idle & slow RPM.
2nd step just rotate that screw clock wise & u will be getting relatively richer mixture for idle/ low RPMs. Dont roatate it eagearly as the mixture ratio changes very quickly while playing with this screw. Just rotatet it ~90 degree ( Quarter round or 1/4 Round). & observe the throttle response @ low rpm if u found some improvement than put back the Carb Cover plate & have try on ur bike Insha Allah u will observe +ve results. U can increase the mixture setting to more rich if required.
In case u cudnt find any improvment than let us know so we can guide u to the next step which is high jet setting( Needle jet Setting) as mentioned by YAMAH 135.
BTW if ur bike is working good on high RPM then needle jet setting wudnt be required.