To design a brochure online, you can use a graphic design tool such as Canva, Adobe InDesign, or Adobe Illustrator. Here are the basic steps to design a brochure using one of these tools:

1. Open the graphic design tool and selec
   t the option to create a new document. Set the dimensions for your brochure.
2. Choose a layout for your brochure. You can start with a pre-designed template or create your own layout from scratch.
3. Add text and images to your brochure. You can use text and image tools to insert and format your content.
4. Use the formatting and design tools to customize the appearance of your brochure. You can change the font, color, and size of your text and add design elements such as shapes, lines, and graphics.
5. Preview your brochure to see how it looks and make any necessary adjustments.
6. Save your brochure as a print-ready file or export it as a PDF to share online.

I hope this helps! Let me know if you have any questions.