There is no rule for it. It really depends on you and your partner. However, we can give you some factors that will help you decide.
On one side, it can be really fun to head off to your honeymoon right after the wedding. In this way, the excitement of the wedding can continue and accompany you throughout your first vacation as Mr. and Mrs. It can really is an opportunity to enjoy and make the most out of the first weeks as a married couple. I know that the weeks right before the wedding are super busy and stressful. Your head will be all over the place, taking care of errands, hosting guests and family, and putting together the last things. So, an immediate getaway can be the perfect way to recover and take some time off for yourself. Plus, can you imagine talking to each other about all the fun you had at you wedding day when it is still fresh in your mind, on a white sand beach?
On the other hand, some couples decide to take some time to relax in a familiar setting after the wedding before leaving for a big trip. And, you could have family members or friends that have come from far to attend your wedding, and you want to have the chance to spend some extra time with them and to host a post-wedding brunch or dinner. You could even head off to your honeymoon just a couple of days after your wedding, so that the memories are still fresh but you also had some time to catch up and rest.