Is there any trick to get the "new" style couplers to couple?  Straight track on teh rails , slide them together and, nothin'.  Am I doing something wrong?

Hello all

I just got my N Scale out of the garage and have decided to make a layout with my grandson. My old locos and cars have a particular coupler. I purchased a new nscale bachmann set and the couplers are very different.  Problem is I cannot get them to connect to each other, nor my older cars and locos. What am I doing wrong. I am sure they should connect to each other, but not sure if they connect to the older stuff.

help