The home page is edited in the Widgets area. From the Dashboard go to Appearance > Widgets.
In there you’ll want to edit Welcome Feature #1 for the left column, Welcome Feature #2 for the center column and Welcome Feature #3 for the right column.
Be sure to twill down the text box in there and make your text edits. And then click save at the bottom of that text box area.
If you want to add or edit the sliders at the top of the home page those are changed or added in the Dashboard > Posts.
All posts that are of category slider will be shown on the home page. You must use a photo that is exactly 950 pixels wide and 300 pixels tall. Be sure to place the photo in the text area as well as in the featured image in the lower right of the Post edits area. And be sure to select “slider” for the category otherwise it won’t show up on the home page. If there is a slider you don’t want to show then just change it to pending or draft.