The same sources of information can give you an estimate of the target times for WODs.
Take a look at the Underdawg times.
If there isn’t an Underdawg time listed for this WOD, take a look at the times others posted on the mainsite and the CF WOD forum here the last time this came up. Discard the very fastest and very slowest and any results not done as rx’ed.
Average the rest and you’ll get an approximate time to shoot for.