There are lots of rumors, mistakes and outright lies online, so double check before you trust. Consider the other person's motives and credentials. The Internet is a great place to develop and practice critical thinking skills. Library staff can show you how they evaluate information online. You may need to watch out for added fees, depending what online service you're using.
Some families avoid all online commerce, while others have rules for purchases.
In either case, monitor bills for anything unexpected. When you know people online only, you don't really know them. Any first meeting with someone should be in a public place, with parents present. Mistakes in Internet addresses can lead to unpleasant results, so don't guess. Make searches as specific as possible and add more words if the search results aren't what you expect.