Hi Jeannette, welcome to the Forum, and to mystery shopping!
When a shop is assigned to you, you will receive an email notifying you of this, and you will always be able to find it on your Assigned Shops page when you login to iSecretShop. If you want to know what;s the status of your requests, or anything about a particular shop, you can always contact the MSP that posted that shop, and their schedulers/editors can help you out :)
If you can't figure out who to contact or how to reach them, you can open a support ticket for iSecretShop and you'll get that info quite quickly.
Good luck, and feel free to write if you need any help!