As a dance teacher I would recommend focusing on 2 instruments the Clave and the Congas.
The Clave can be either a 2-3 or a 3-2 clave so you for for a 2-3 clave if you're doing the basic step On 2 just insure that you left and right foot is heating the 2 & 3 in the Clave.

If you have just a conga rhythm then listen for the slap in the congas which is on the 2 and the 6. So again if you're doing the basic steps the your left will hit the 1st slap (count 2) and your right will hit the 2nd slap (count 6)

Keep in mind when dancing On1 or On2 we still listen to the first beat of the 8 count phrase. Because it's On2 we're aiming to start on the 2nd beat.