[Gmail] How to read email

❍ Messages as read or unread

     -  White background / Bold title: unread

     -  Gray Background / Thin Title: read

❍ Group emails into conversations

You can choose whether replies to emails are grouped in conversations, or if each email shows up in your inbox separately. 

① In the top right, click Settings >See all settings

② Scroll down to the "Email Threading" section

③ Check or uncheck the box for Conversation view.     

❍  Find labels setting & make change

 ① In the top right, click Settings     >See all settings

 ② At the top, choose a settings page,  click Labels

 ③ Set the range to be displayed in the label list

 ④ Choose between Show or Hide for each category.