Has anyone ever couchsurfed? (Couchsurfing.com)

If so, any tips for a potential couchsurfer? Is it acceptable for people to couchsurf within their own country (USA)? I currently am temporarily living on the other side of the country and would like to explore all of the areas around me. I saw some people willing to host on the couchsurfing website but I’m too scared to take the plunge and send them a message…