I hope you are well today and thank you for your question.
The following plugin provides contact us widget and posts widgets so you can use it.
To display the widgets in the right sidebar, just add the widgets in the right sidebar from the widgets screen in the admin area as shown in the attached screenshot.
It worked. I appreciate your help. I have another question though,
How can I change the front size of my post and its color. Please check the attached file for reference.