BuddyPress.org

I have just started making my site and have no knowledge of coding at all. Would someone be able to show me a quick example of what to insert into my code to limit members posts to say 100 words.
It sort of explains on the link but It makes no sense to me.
Thankyou so much to whoever can help.
This is the last thing I need before I make it live so any help is very much appreciated.