Full post in Homepage e customize Read More

Hello to all! I need to change the display of the post in Homepage. I would like to be able to view full post and decide at what point I insert the Read More. The theme has flouted the Read More inserted by the editor. Also I would also be able to customize the Read More. I do not like to appear only […]. Prefer to submit “Continue reading”. And it would be nice to be able to turn into a colored button. How could I achieve this? I’ve created a child theme. Thank you and forgive me for my bad English.