Hello @tsuzan1- thanks for the support.
Hello @marina00007,
Making it bit clearer, follow the steps mentioned below:
1.First of all you need to create & publish couples of pages(like Home, Blog, About, Features, Services) and also upload feature images to those pages.
2. Next, Go to Appearance-> Customize-> Static Front Page. Choose A static page. Select Home as Front Page and Blog as Posts Page.
3. Now Go to Customize-> Home/Front Featured Slider-> Enable Slider Options-> Check Enable Slider On.
4. Lastly, Go to Appearance-> Customize-> Home/Front featured slider-> Select slider from page. Select the pages created in step 1.
Click Save and Publish after you are done.
This should be the trick to add slider images from your selected pages.
Hope this helps resolve your issue.
Best Regards.