bulk deleting in gmail

Question

you can only do bulk actions on a pc  
 
   Gmail help  reference on deleting mail >> https://support.google.com/mail/answer/7401

before you delete i suggest you read this http://gmail-miscellany.blogspot.com/2012/10/how-gmail-stores-your-mail.html  because gmail only has 1 copy of each email and it is only in one place no matter how many labels it has so if you delete it from one view you are deleting the one and only copy of that email  
 
also note - if you have conversation view on  it affects how you delete emails - if you get a reply to a sent email  , OR you reply to a received email and you delete the email or the reply   - they will both be deleted unless you pull down the arrow on the right of the email you want to delete and select delete this message ( or turn conversation view off in gmails settings >> click the  gear  picture in gmail > settings >  in the general category turn conversation view off > save  http://support.google.com/mail/answer/5900?hl=en )

to select multiple mail   ( see image below    )    
Open the label (or, your Inbox, or Sent Mail, etc) containing the messages you'd like to select.
Click the Select: All link above your messages.
Click the link that says Select all [number] conversations in [current view].
Select the action you'd like to do 
  to search eg by date / sender etc if you need to delete or move or action certain mail only  see https://support.google.com/mail/answer/7190?hl=en