In order to start performing missions for a Social Club, you must first renovate the Social Club. The icon for a Social Club is a Dark Red House and it's pretty tough to miss on your map. Renovating it costs money (all fall into a price range between 500 to 10000 dollars), so make sure you have some pocket change on you before renovating a Club.
After renovating a Club, you will then see three smaller icons of houses (they will be in white hexagons) pop up extremely close to the (now white) icon of the Social Club. Proceed to the top floor of the Club you have renovated. Up here will be three missions and each one will be located on a piece of furniture (a chair, wardrobe, etc. - don't ask me why this is, I don't know either). Walk up to a mission and it will tell you the description of it, the reward for completing it, as well as the difficulty rating.
All you have to do at this point is just complete all three of these missions at ONE Social Club and the achievement will be yours.
I hope this helped, and have a nice day!