get foot in the door

get a/(one's) foot in the door

To have a chance to do something that could lead to further opportunities. The phrase is often used to refer to employment. An internship might not sound very interesting, but it's a great way to get your foot in the door at this company.
See also: door, foot, get
Farlex Dictionary of Idioms.

get one's foot in the door

Fig. to complete the first step in a process. (Alludes to people selling things from door-to-door and blocking the door with a foot so it cannot be closed on them.) I think I could get the job if I could only get my foot in the door. It pays to get your foot in the door. Try to get an appointment with the boss.
See also: door, foot, get
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • a foot in the door
  • a leg in the door
  • a toe in the door
  • foot in the door
  • foot in the door, get one's
  • get a foot in the door
  • get a/(one's) foot in the door
  • get a/(one's) leg in the door
  • have a foot in the door
  • have a/(one's) foot in the door