Hi Adeola,
My name is Samuel King and I am the new owner of Organized Themes.
Let me see if I can help you out here.
If you want to make the text widget 100%, you will first have to create a CSS rule for it, and then apply that rule to that text widget.
To do this, please download this plugin here https://wordpress.org/plugins/widget-css-classes/
Install and activate this plugin.
Next navigate to your custom css setting, it can be found under customize=>advanced=>custom css.
Paste this code below in the field
#home-widgets .widget.hometext-block {
width: 100%;
}
Finally, add your text widget to the home page and under the new settings that says css classes, paste this text there
hometext-block
This will make that text widget 100%.
Let me know if you run into any issues.
Regards
Sam