Thank you for reaching out.

To change your website logo, navigate to the theme Customizer > Site Identity > Site Title and Logo Control. Here is a screencast for your reference:
https://share.zight.com/bLubwjke

To change your website color, navigate to the theme Customizer > Colors & Fonts > Color – Typography. Here is a screencast for your reference:
https://share.zight.com/o0uLmv7R

I hope this helps. Please let us know how we can help further.

Cheers,
Eze