The best way you can protect yourself while online is changing your passwords frequently! Passwords should have at least 6-8 characters and include all types of things like: letters, capitals and lower case, characters, and numbers.
When you use a public WiFi remember that you are sharing the connection with people you do not know! Do not go to password protected sites, share information or download things while you are on an open network.
If shopping online remember to check the sellers information. DO not share credit card information with them directly and always be sure to read the return policies and reviews.