On main dashboard do the following things from the navigation specified
If you don't have a logo yet, you can start by changing the logo to text so that the name of you site will appear in the logo section.
We highly recommend you to this rather than waiting to launch your website until you found the perfect logo or have money to invest in a designer.
The color scheme of the theme will affect the color of your header, sidebar, links etc.
This color schemes have been created by designers to make sure your website looks professional even if you have no design knowledge.
Choose Lossy Compression for your image optimization. This will help reduce image size and improve the loading speed of your website. If you want more technical information about this feature, you can check out this blog post.
