Back in the '70s, the main use of the net was file transfers. One of the early protocols, file transfer protocol, or ftp, is still used a lot today. FTP-PM comes with Warp. The next big use of the internet was electronic mail, or email. Warp comes with Ulti Mail Lite which is functional but not the best product around.
Most people use mail a lot, and it is probably worthwhile to buy a commercial replacement.
Other popular services include groupware tools for newsgroups and chat. Newsgroups are a network of servers with tens of thousands of discussion groups where participants can read recent postings of other participants, and respond with comments of their own. This is very useful for asking questions on subjects you're interested in and benefitting from the expertise of other participants. There are many commercial alternatives, the most useful advantage being the ability to handle binary attachments which are prevalent on some newsgroups. Find chat software at the same places you can find other internet tools.