Where can I find browsing and buying behavior of Internet users?
Go to Mintel. Categories include eCommerce. Mintel reports include interactive Databooks, some which feature questions regarding respondents' online browsing and purchasing habits
Go to Passport (Consumer Industries) and then hover over Consumers in the top menu. Select Digital Consumer to access a dashboard featuring statistics, analyses, country reports, and more.
Use SimplyAnalytics. Users have a choice to either create an account to log-in using their e-mail address or click a button to log-in as a guest.
Go to Statista to access eCommerce and Internet statistics and reports. Also, check out the Digital Market Outlook and Global Consumer Survey
For research on Internet usage, go to Pew Research Center: Internet & Technology.
Also take a look at Google Trends to "explore what world is searching".