[rotorwrench]

Are you referring to while the vehicle is running but not in forward motion or it just won't go into 2nd under any circumstance while running?

The second gear is shifted into engagement though the synchronizer which is a pretty easy action normally. If it will shift with the engine off but not so with it running then I would suspect the clutch or its adjustment first.

I say this with a word of caution due to where the vehicle may be setting near obstacles or other vehicles. If the car is clear of obstacles, will the engine turn over while in gear with the clutch disengaged? If it tries to move then the clutch is not fully disengaged.