After Effects KeyFrame Question

I am not sure if this is the right forum but i didnt see one dedicated to after effects or motion graphics and this seemed like the most relavent, if there is a better place please move it.

I am brand new to after effects, want to make somerthing move from point A to point B then wait at point B until i tell it to move again.

so i would want 4 key frames

A------>B------->B------->C
where it starts at point A moves to point B and then stays at point be then moves to point C

all i can seem to make is like this
A----->B----------------->C

so point B just slowly goes to point C…I cant seem to figure out how to add a keyframe without changing anything? so far i have added a keyframe from changing it then changing it back but that doesnt seem very efficent so i am sure theres a better way. I am actually a flash developer and I am used to keyframes but they seem totally different in after effects. Any help is appriciated.

Thanks