The benefit of a wedding rehearsal is to ensure that you and your partner know just how things will progress. It also helps if your wedding party can also attend the rehearsal, so they too know what to expect on the day. A rehearsal provides a great opportunity for the whole wedding party to ask questions, make any changes if needed and feel nice and comfortable so that the actual day runs smoothly.
The rehearsal is usually held about 2 weeks prior to the big day, but doesn't necessarily need to be held at the actual venue. If you're doing an outdoor wedding, the rehearsal can be held at a local park similar to the actual venue. Alternatively, if the wedding is taking place indoors, if the venue is available, it's always best to try and do it there, but not imperative. A home, such as yours or your parents can also be used.