Gmail will usually put new emails at the top. The exceptions are if it is considered spam or you have filtered your emails to go into folders (labels).
How can you tell they are new?
It will also usually be white and go grey when you have read it.
If it has been filtered or moved by Gmail look in your All mail label/folder on the left of the browser screen when Gmail is open. Your email swill be in date order so the newest will be at the top.If you accidentally archive something before you are ready, ‘All mail’ can be a God send!
Other places to look
The spam and trash labels are always a good place to check as well (also on the left navigation bar).
In summary, check your All mail, Spam and Trash folders for emails if you cannot find them but you are expecting them.
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