Choose Edit > Find (Ctrl/Command+F). Type the text you want to search for in the text box on the Find toolbar. To replace text, click Replace With to expand the toolbar, then type the replacement text in the Replace With text box. Finds only occurrences of the complete word you type in the text box.
For More Information Please Refer: https://helpx.adobe.com/in/acrobat/using/searching-pdfs.html