Hello,
The easiest way I can think of to do this is to find the folder you want to hide from the Guest (follow these steps from the Admin account, note that this will also hide the folder from all non-admin users, not just the Guest account), right-click it, select "Properties", then go to the Security tab. Click on the "Edit" button, then highlight the row "Users (yourPCName\Users)", and in the bottom, under the column that says "Deny", check the box for "Read and execute", and the boxes for "List folder contents" and "Read" will also be checked, effectively denying all non-admin users from seeing or running anything inside the folder.
If you found that hard to understand, I've attached a screenshot of the Permissions editor that...