To begin, you make a decision: Do you want to try out Second Life with a temporary trial account and avatar? Or are you ready to set up your own permanent account? Either approach is free.
For a trial account and avatar, please send an email to our helpers. They'll give you a username and password to allow you ten days of exploring SL.
For a permanant account, you sign up through secondlife.com. You pick your own starting avatar, fill out some secure information about yourself, and choose your own username and password.
In either case, you need to download some free computer software called a viewer. A viewer is like a browser (Chrome, Safari, Firefox, etc.) except that it handles the 3-dimensional graphics of Second Life. (At this time, phones and tablets are not powerful enough to do the job. Computers made within the last few years should be fine.)
Several free viewers are available. They work on both Windows and Macintosh operating systems (and some on Linux). They all do the same basic things, but their interfaces differ, and some have additional features. The most popular seems to be Firestorm.
If you sign up for a permanent account, you'll be led to download the "official" Second Life viewer. But any other viewer will work. Our helpers can assist you in deciding and in downloading one.
You can consult this page for ideas about what to do after you log in.