How do I find word or phrase in email or a web page

Here is an extract from Ch 5 of the iPad User Guide regarding searching emails -

Searching mail You can search the To, From, Subject and body text of email messages. Mail searches the downloaded messages in the current mailbox. For iCloud, Exchange, and some IMAP mail accounts, you can also search messages on the server.

Search email messages: Open a mailbox, scroll to the top, and enter text in the Search field. Tap From, To, Subject, or All to choose which fields you want to search. If your mail account supports it, messages on the server are also searched.

Mail messages can also be included in searches from the Home screen. See “Searching” on page 32.

As for the web page, this will vary from site to site. There may be a search box such as in Wikipedia or if you a searching a PDF therein you could open it in a programme such as iBooks, Goodreader etc and search within that app.

Or just hit the google search bar, look at the top right of the keyboard pane where it says "find on this page", type what you are looking for in the box.