Go to your "member area", click the "store" icon link. You will have to activate your store for the level you desire. Then proceed to create a store front. You may also upload a logo for your store if you have one. VintageAuctionGalleries.com does allow html, change from basic text editor (white background) to html editor (blue background) by clicking the "<>" toggle, copy and paste the code (or write it yourself) into the editor. Click the "<>" again and see the finished product.

Similarly, you can create your own design using the basic text editor to enhance font, color, tables, highlighted text and alignments. Click "<>", to see the code.
Just follow the other instructions on the "Create Store" page.