I had a look at your Machine Manual Online.
I have H/V Designer1 machine so I am familiar with the features of these machines.
I have a Windows Computer so am not familiar with Macs but hopefully Betty will jump in here if my information is incorrect.
Your embroidery machine requires the VIP3 Stitch format in order to stitch the design out.
Your Mac computer has a Main Drive that all your folders and files are storesd on.
When you plug a USB Stick into your computer it will show up as another Drive letter.
It may show it as a Removeable Device Drive.
When you purchase and download designs to your computer you usually store them in a folder on the Main Drive.
The downloaded designs are usally in a Zipped File which should contain your VIP3 Stitch File format and may aslo contain other stich file format for other machines and also a color chart for the design that comes as a text, or word or pdf file.
You will have to unzip the zip file or extract the files from within the zip file and place the stitch files in a new folder on your Main Drive.
Name the folder so you remember where the design stitch files are such as Extracted Designs.
Do not delete the Zip file after extracting the stitch files from it as this still hold the original files.
On a Windows Computer In order to get the VIP3 Stitch file to a USB Stick you would copy the VIP3 file from the folder that you stored the stitch file in and paste it to the USB Drive which is your USB Stick when it is plugged into your computer.
Or you could drag the VIP3 Stitch file from the Folder and drop it on to or into the USB Drive which is the USB Stick when plugged into a Windows computer.
BUT A Mac Computers handles the stitch files differently so you can't do the copy and paste or drag and drop
Please Read Betty's post below which explains the need to have software in order to get the stitch file from your Mac Computer to your USB Stick so your machine will read the file correctly
The Essentials software makes it easy for you save the stitch file from your Mac computer to your USB stick for your machine.
You simply open or import the design into Essentials and if you want add to or edit the design and then you save the stitch file to your USB stitck using the Save Stitch File As Option.
Have a look at this Video that shows how to save design stitch file in Essentials to a USB Stick.
http://www.youtube.com/watch?v=VlGuvT_O ... e=youtu.be
Before placing any new designs on your USB Stick read your Manual on how to save the pre loaded designs that are on the USB Stick to a folder on your computer. This ensures that you don't loose those designs.
You may also want to check with your machine dealer about using other Brands of USB Stitcks in your embroidery machine.
Usually you can use other brands of USB Sticks in Viking machines but it is best you check this.
It is a really good idea to have more than one USB stitck for your embroidery machine.
And you can usually buy them at a computer store at a much better price than buying another one from your machine dealer.
You should take your time and stitch out a few of the pre loaded designs that came on your USB stick so you get familiar with the embroidery features on your machine.
Your machine has several embroidery design editing functions that can be done right on the screen of your machine so take the time to learn what they can do for you.
Essentials has many design editing functions and would be a great complimentry program to the editing your machine has.
I find that it is so much easier to work on a computer screen than on an embroidery machine screen when editing and working with designs.
Please feel free to ask questions and on't be shy as we are here to help you.
We were all new to embroidery at one time or another and we are all still learning new things too.
See Betty's post below