You gain access to the product directly after purchase.
Your purchase is sent to you via the JVZoo, Clickbank, WarriorPlus or Warrior Payments system so it'll be with you (more or less) as soon as you place your order. You'll also get an email with a link to the delivery too.
If it's a membership you should get access to the account creation instead.
However if there's any problem to access your purchase please submit a support ticket and we will help you ASAP.