How do I customize my avatar?

[hahaha83]

Welcome to SL :)

Check out http://community.secondlife.com/t5/English-Knowledge-Base/Editing-your-appearance/ta-p/700709

If you have more questions you can add "Comments" here to your post.

[Venus Petrov]

I just sent you a notecard full of helpful information for newbies, including where to find good free skins, clothes, and more!  Enjoy!

[PeterCanessa Oh]

If you have just joined SL and downloaded the viewer you may be using the 'basic mode'  which has quite restricted abilities.  In particular you can only use one of the presets avatars and cannot buy anything.  This is so that you can get used to the simple functions in SL - walking, flying, teleporting, text-chatting and interacting with objects.

When you feel comfortable with those you need to log out of SL and then back in in order to select 'advanced mode', which has all the functionality enabled.

Please see this page for details: http://community.secondlife.com/t5/English-Knowled​ge-Base/Basic-mode-FAQ/ta-p/733541