I am confused about how, once saved, to drag or add my designs to set them up to be sold. I don’t know what jpeg, and the various methods are for completing tasks. HEELP!
The first view you see is where you upload all your design right? Under Spreadshirt
You now want to edit and add products to that design hovering over the design and you click on the design you want to edit
You then choose a sales channel (this only shows up if you sell on the Marketplace and in your own merch shop. If you only plan to sell in your merch shop this step is skipped 
Then you need to edit yor product selection. So you click on “Edit product selection”
You can decide to activate approx 100 products. Most products work with pixel graphics. But a selected few only work with vector graphics. The difference can be found here:
You simpley activate and deactivate the products you would like to add and then click on “Done” at the bottom of the page.
Then you want to edit the placement or the default color or restrict certain colors for certain products and certain designs. You can do this on an individual product editing level.
You can then drag and drop the placement, edit the design size, decide on the default display color, deactivate certain product colors, and decide whether you want to display the design on the front or on the back.
One you’re done click on “Apply”. You repeat these steps for all the products you would like to edit and once you’re happy with all the editing you can click on “Save as Template”, name the template and apply the saved template to the next design you upload. Then click “Next” at the bottom of the page.
Now you have to add some details to your designs, such as name, description and some tags. This will help with the search engines.
You’re basically done. Now you only need to price your products. This is done by going to your shop admin, clicking on Prices & Promos
And now you set the retail price for all of the individual product types in your shop.
Let me know if you have any remaining questions.
Best to also have a look at our help pages
https://help.spreadshop.com/hc/en-us/categories/360002237799-Partner-Help