Turbo clutch question
 

My clutch pedal doesn't feel so smooth as if it's on a cable that feels like it's about to snap tbh, sort of catches right at the top as you take your foot off it , I know it's a hydraulic clutch could this mean new fluid and lots of wd40 on the pedal ? What fluid should I top it up with and where abouts is the resivoir ? Had a search and it's on the left of the ic thought that was for the diff fluid there (little dipstick ) sorry if it sounds a dumb question , help please
Many thanks

Its next to the brake fluid. Dot4 will be fine