Dance which all beginners should take at a time (3-4)
I believe the answer is:
one-step
'dance which all' is the definition.
'one step' can be an answer for 'dance' (I've seen this before). I am unsure of the remainder of the definition.
'beginners should take at a time' is the wordplay.
'beginners' says to take the initial letters.
'at' says to put letters next to each other (I've seen this in other clues).
'a' becomes 'one'.
'time' becomes 'ep' (I can't justify this - if you can you should give a lot more credence to this answer).
The initial letters of 'should take' is 'st'.
'st' put after 'one' is 'onest'.
'onest'+'ep'='ONE-STEP'
Can you help me to learn more?
(Other definitions for one-step that I've seen before include "Kind of foxtrot" , "Style of foxtrot" , "Vigorous dance" , "(Very short?) ballroom dance" , "Foxtrot's precursor" .)