Another thing if you wish, is to choose "invisble" if you do not feel like everyone know when you have logged in, and just feel like reading posts but not post or reply.
If you even still want to post/reply you can stay under that choice of invisble or shown.
Like others have said, no one sees your real name,e-mail,address, etc. so it's safe in that respect.
And to feel safer, don't put anything publicly where anyone can read, if you do not want people to know of personal things, sort of like what someone said here, if it's something you wouldn't want someone to read on a postcard you were sending to someone, you may want to see things in that way in relation to what you wish to post for others to see. You'll find in time you'll overcome that unsafe feeling you are having, PC is not like other sites.
I hope you enjoy your time here at PC.