Hi,
To remove these logo or text follow below steps:
1. Go to Dashboard->Appearance -> Customize -> Front Page -> Slider
2. Click on “Edit Content” from Static Slide Content
3. Select all text and change it ( Its white on white, that’s why you are having difficulty)
4. Click “Save & close“
https://optimizerwp.com/documentation/setting-up-static-image-slider/
Thanks