Too many things to be described in a discussion entry Jeniffer.
Take a look at this link maybe it helps http://support.italki.com/home
To keep it short
With italki you can.
Find teachers for a number of languages that teach through Skype for a set price.
Post Notebook entries in the language you are interested. This entries can be corrected by any visitor. You call also correct Notebook entries and help others as well.
You can create and/or participate in Discussions to improve your writting skills.
You can post short questions or answer simple questions in the language of your choice.
Good luck and have fun.